Chip Somodevilla / Getty Images file

Attorney General Eric Holder testifies before the Senate Judiciary Committee on March 6.

The Obama administration publicly acknowledged for the first time Wednesday that U.S. drone strikes have killed four American citizens since 2009, including the previously undisclosed death of a North Carolina resident who left the United States for Pakistan and was later indicted on federal terrorism charges.

Attorney General Eric Holder, in a letter to congressional leaders and chairman of key congressional committees made public on the eve of what was billed as a major counterterrorism speech by President Barack Obama, also confirmed the deaths in drone attacks in Yemen of three other Americans that already had been widely reported: those of radical cleric Anwar Al-Awlaki , his teenage son, Abd al-Rahmn Anwar al-Awlaki; and Samir Khan, the American who ran al Qaeda’s web-based propaganda magazine Inspire.  Previously the Obama administration had only acknowledged the senior Awlaki’s killing and refused to publicly confirm or deny reports of the other deaths.

The letter also confirmed that U.S. drones had killed Jude Kenan Mohammed of Raleigh, N.C., more than a  year after a local news report quoted a friend as saying he had died in an attack in Pakistan in November 2011.

Holder said in the letter that the senior Awlaki was the only U.S. citizen targeted in a drone strike.

Anonymous / AP

Anwar al-Awlaki, a U.S.-born Yemeni cleric and recruiter for al Qaeda in the Arabian Peninsula in Yemen, is shown in an October 2008 file photo.

He also provided new details about what the U.S. says were Awlaki's operational roles in terror plots, including his role in a 2010 attempt to bomb cargo planes by putting bombs in printer cartridges.

It also included an explicit explanation of the U.S. policy for targeted killings of Americans, much of which was included in a “white paper” obtained by NBC News in February.

Mohammed’s death appears to have been news to the FBI, which as of Thursday still listed him on its “most wanted” list, saying, “On July 22, 2009, a federal grand jury in North Carolina indicted Jude Kenan Mohammad for conspiracy to provide material support to terrorists and conspiracy to murder, kidnap, maim, and injure persons in a foreign country. Mohammad is at large … (and) is believed to be in Pakistan.”

A law enforcement official who spoke on condition of anonymity told NBC News: “We don’t know when he was killed. That fact was classified.”

FBI spokeswoman Shelley Lynch said in an email: "Jude Kenan Mohammed remained wanted until there was official confirmation of death.  Until now, the matter was classified and it is now appropriate for the wanted poster to be removed from our website." 

Obama is expected to discuss the drone program Thursday in a speech at the National Defense University in Washington, D.C.

Release of Holder’s letter came as classified documents obtained by NBC News raised new questions about the CIA-run drone program and whether it is consistent with public comments by Obama and other administration officials describing  the strikes as “very precise” and targeted at specific al Qaeda operatives and their associates. In fact, the documents show, the agency has frequently attacked low-level militants and foreign fighters in Pakistan whose names and nationalities were not known, as well as militant groups not directly connected to al Qaeda.

The documents, similar to those recently reported by McClatchy Newspapers, offer a window into the secretive drone program and how its actual operations sometimes differ from the public accounts provided by the administration.

They appear to officially confirm that the agency has engaged in “signature strikes” – a much discussed and controversial practice that has never been publicly acknowledged -- in which CIA drone operators target individuals based on the “signature characteristics” of suspects but whose actual identities are not clear.

They surface at a time that U.S officials appear to be scaling back the drone program – amid warnings from some  former military and intelligence officials that the attacks may be creating a backlash harmful to U.S. interests in the long run.

 When Obama was asked about the drone program last year during a Google News forum, he called it “a targeted, focused effort at people who are on a list of active terrorists.” In an April 2012 speech, then White House counter-terrorism adviser and now CIA Director John Brennan said: “The United States Government conducts targeted strikes against specific al Qaeda terrorists,” while acknowledging that drone targets included “associated forces.”

But a CIA list of 53 drone strikes in the fall of 2010 indicates that fewer than half – 22 -- listed al Qaeda operatives as the targets. Other strikes were aimed at targets that included suspected members of the militant al-Haqqani network in Pakistan, which is believed to have harbored and worked with al Qaeda; members of the Pakistani Taliban, an Islamic fundamentalist military group that aims to overthrow the Pakistani government; and members of another Pakistani terrorist network identified as the “Commander Nazir Group.”  Fourteen of the strikes listed the targets only as “other militants.”

Agency lists for other periods show a higher proportion of strikes being specifically aimed at Al Qaeda operatives. For example, during a nine month period between January and September 2011, 28 out of 42 strikes listed al Qaeda members as targets.

But in other accounts of the strikes, agency officials refer to the targeting of individuals whose identifies do not appear to be known. One 2009 attack was described as being aimed at “military aged males”  at a site “associated with al Qaeda explosives training.” Another, in 2010, described the target as “four adult males conducting weapons training.”

The CIA and White House did not respond to requests for comment about the documents. But U.S. officials have vigorously defended the drone program and their public accounts of it, while saying they are limited in what they can say because of its classified nature and the potential impacts of full public disclosure in Pakistan. As for the use of signature strikes , they have argued that “when you have a bunch of guys building explosives, you don’t need to know who they are. They are an imminent threat.”

NBC News’ Pete Williams, Chuck Todd and Tom Curry contributed to this report.

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A tornado warning was issued for parts of Massachusetts on Wednesday evening as a severe weather storm capable of producing a twister was spotted on radar, forecasters said.

The "dangerous storm" was located near Salem, or 11 miles northeast of Amherst, the National Weather Service warned.

Residents were told to take cover. No confirmed tornado was spotted, however, and about 45 minutes later the Weather Service changed their warning in the area to one alerting of possible severe thunderstorms with the potential for damaging winds of more than 60 mph.

The warnings were issued as the same storm front that spawned downpours and deadly tornadoes in Oklahoma marched east, forecasters said.

An area stretching from the Appalachians into the lower Great Lakes and New England was at "slight risk" of severe thunderstorms Wednesday night into Thursday.

Stronger and sometimes severe storms carrying gusty winds and hail were seen in southwestern Pennsylvania along the crest of the Appalachian range and into the Lower Great Lakes, according to the Weather Service.

The areas at risk for thunderstorms included Indianapolis, Columbus, Detroit, Boston and Cleveland but also stretched into Western New York and Connecticut. 

An earlier threat of possible isolated tornadoes farther west, in Western Ohio into the Tennessee Valley, "appears to have diminished" because of cooling from cloud cover, forecasters said.

However at least one funnel cloud was reported in central Florida in the town of Viera, according to NBC station WESH TV. 

The Northern Rockies area — from Northeast Wyoming through Western Montana — could also see storms with severe hail and wind, the Weather Service said.

Get more from weather.com

Weather.com's forecast showed a map outlining the main area of risk, which stretched from Buffalo to Charleston. It also said the main danger would be from high winds and hail, but cautioned there was a “slight risk” of tornadoes.

"Other showers and thunderstorms are possible from the remainder of the Northeast and Great Lakes into the South," it said.

"A few isolated severe thunderstorms producing damaging wind gusts and hail are possible in the lower Mississippi Valley. Showers and thunderstorms continue from the Northeast to the Southeast Thursday, although the severe threat is even lower," weather.com added.

Parts of northeast Kentucky, Ohio, southeast Michigan, western Pennsylvania and western New York were given a 3 out of 10 on Weather.com's tornado probability scale, with 10 representing the highest probability of twisters. The cities of Cincinnati, Columbus, Detroit, Pittsburgh and Buffalo were all included in this risk area.

Meanwhile, a tornado rating of 2 was given to Tennessee, most of Kentucky, much of eastern Indiana, parts of southern and eastern Michigan, eastern West Virginia, much of Pennsylvania and much of upstate New York.

Connecticut was hit by strong storms that caused some damage in northern parts of the state on Tuesday, NBCConnecticut.com reported.

A storm moved through Copake, New York, just before 5 p.m. and headed southeast through Massachusetts and along the extreme northwest corner of Connecticut, the station said. Downed trees and power lines were found in Falls Village and lightning strikes came close to homes in Cornwall.

A tree fell on cars in the high school parking lot in Falls Village. "It's just a car. We're just here to make sure all the kids were safe," said Patricia Chamberlain, superintendent, whose car was among those hit.

Thunder, lightning, high winds and hail were reported in several Conn. towns, including Salisbury, Canaan, South Windsor and Manchester.

Related:

• Full coverage of Oklahoma tornadoes
• 9-year-old, 65-year-old among first tornado victims identified
• Before and after: Tornado cuts devastating path through Oklahoma

The earth itself was at least partially to blame for why desperate schoolchildren in Moore, Okla., had nowhere to hide from Monday’s devastating tornado.

Much of the soil in Oklahoma, including Moore, is red clay -- a porous substance that makes foundations settle and basements and underground tornado shelters leak. “That’s the reason we don’t have basements,” said Tom Bennett of Tulsa, past president of the National Storm Shelter Association. In greater Oklahoma City, which includes Moore, only 3.5 percent of homes have basements, according to Reuters.

But it wasn’t just the ground under residents’ feet that was to blame. The region’s politics and economy also were factors.

“This is a red state,” said state Rep. Richard Morrissette, D-Oklahoma City, who has introduced several unsuccessful bills in the state Legislature to require so-called “safe rooms,” shelters or anti-tornado construction in homes and trailer parks. “People don’t like anything that is mandated. They don’t like it when the government says they have to do something.”

That makes Oklahoma similar to other states in Tornado Alley. “I am unaware of any jurisdiction that requires safe rooms in private homes,” said Corey Schultz, a Kansas architect who specializes in building safe rooms for schools. And only one state – Alabama – requires them in schools, he said.

Though the mayor of Moore said Wednesday he now wants the city to require shelters in private homes, Oklahoma, like other states prone to tornadoes, prefers to encourage the construction of shelters. The state has emphasized using federal funds to underwrite the optional construction of specially reinforced, above-ground “safe rooms” inside private homes rather than community tornado shelters.

But building a steel room on a concrete slab adds thousands to the price of a new home in a market where a typical property is worth $108,000. And for homeowners, spending $2,500 and up to add tornado protection to existing homes often isn’t feasible without assistance in a state where the median income is $44,000 -- $8,000 below the national figure.

That’s a tough sell, even though it could mean the difference between life and death, said Bennett, the former president of the storm shelter association.

“In-residence’ safe rooms’ are the way to go,” he said. The rooms are built to withstand EF 5 tornadoes, with winds of 250 mph – in excess of the 210 mph recorded in Moore. “But half the population can’t afford it or doesn’t have a place to put it because they live in apartments.”

FEMA, which has programs to offset the costs, estimates it costs between $6,600 and $8,700 for a steel-reinforced 8-by-8-foot room, and much more for a larger space.

In 2012, the state launched a new program to make construction of the rooms less costly. SoonerSafe pays homeowners 75 percent of the cost of building a safe room, up to $2,000. But again, the money is federal, pulled from the state’s unused FEMA funds, and winners are chosen via lottery. In 2012, 16,000 homeowners applied, and 500 “won” the reimbursements via random drawing.

“Oklahoma’s SoonerSafe Safe Room Rebate Program is a model for supporting the construction of safe rooms through the Hazard Mitigation Grant Program Grants,” said FEMA spokesman Dan Watson.

Localities can also apply for another pool of federal money, as the City of Moore was attempting to do. Moore wanted $2 million in rebates for 800 homeowners to build safe rooms, and had submitted an emergency plan to the state and FEMA as part of the application process. But according to the city’s website, changes in federal regulations created a “moving target” and delayed the program.

FEMA’s Watson said that in the past 20 years, “FEMA has invested more than $57 million in 11,768 private and public safe rooms in Oklahoma, more structures than any other state. Many were in the same area as yesterday’s tornado.”

“The State of Oklahoma has been a great partner in providing innovative mitigation solutions to residents,” he added.

Despite the construction and subsidies, Bennett estimated that less than a fifth of the state’s 4 million residents have access to meaningful private shelter from tornadoes. In Moore, according to the New York Times, only about 10 percent of homes have them.

Schultz, the Kansas architect, said Oklahoma schools are not required to have storm shelters, but can apply for federal funding to build them. Albert Ashwood, who heads the Oklahoma Department of Emergency Management, said at a press conference Tuesday that safe rooms at more than 100 schools had been funded via FEMA, but that the two schools hit in Oklahoma, Briarwood Elementary and Plaza Towers Elementary, were not among them. There are more than 1,800 public schools in Oklahoma.

“You have limited funds that are based on disasters you’ve had in the past,” he said. “When you have limited funds, you set priorities on what schools you want to ask for.”

He also said that his department was trying to determine how many schools in the state had safe rooms.

The preference for safe rooms in private residences rather than public structures is only partly about political philosophy. It’s also based on a safety calculation. Using your own shelter or a neighbor’s shelter can be faster than trying to reach a central location.

“I don’t think it’s a good idea to drive across town when there’s a tornado,” said Bennett. “That’s where community shelters fall short.”

On the City of Moore’s website, an Emergency Management notice explains that Moore has no community shelter because there is no building suitable for one, and because “overall, people face less risk by taking shelter in a reasonably well-constructed residence!”

Next door in Kansas, however, Schultz says an equally beet-red state seems to have decided to steer its disaster money to creating more public shelters. Schultz says that his state, like Oklahoma, depends on FEMA funding for tornado shelters, but has focused on adding safe rooms to schools. In 1999, tornadoes hit schools in Wichita, and though no one was killed, “that opened eyes.”

“When we send our kids to school there are two things we take for granted,” said Schultz. “One is that they’re learning something. The other is that they’ll come home safe. “

“The Enterprise tornado and now this tornado show us that’s not always the case. I truly believe in shelters in schools for that reason.”

Bennett said that he is now receiving the same kind of back-channel signals that he got after the 2007 tornado in Enterprise, Ala., where a tornado killed seven at the local high school. That led Alabama to require schools to include safe rooms or to close during tornado watches. “Oklahoma may be headed in the direction of Alabama,” he said.

On Wednesday, Moore mayor Glenn Lewis said he would propose a new ordinance requiring shelters in newly constructed single and multi-family homes. "We'll try to get it passed as soon as I can," he told CNN.

And Chris Shatswell, an Oklahoma native who now lives in Fort Worth, Texas, has created an online petition via Change.org to get storm shelters in Oklahoma schools.

So while Morrissette, the Oklahoma legislator, worries that the current attention to increasing the supply of shelters may be short-lived, Bennett is more optimistic. “This has a shelf-life. The story of the kids in Moore has an impact,” he said.

Mark Schone is an investigative editor for NBC News; Nidhi Subbaraman is a contributing technology and science writer for NBC News; Alan Boyle, NBC News Digital science editor, also contributed to this report.

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A West Point Military Academy staff member has been accused of planting hidden cameras in the shower and locker room facilities of female cadets, U.S. military and Pentagon officials told NBC News.

Sgt. 1st Class Michael McClendon has been relieved of his duties at West Point. McClendon was charged with four counts of indecent acts, dereliction of duty, cruelty and maltreatment and violations of good order and discipline. He has been transferred to Fort Drum in upstate New York.

McClendon, a decorated combat veteran of the war in Iraq, was a staff advisor responsible for the health, welfare and discipline of 125 cadets, defense officials said.

He received the Bronze Star and combat action badge during his combat tour in Iraq.

The story was first reported by the New York Times.

Separately, the Army on Tuesday said Brigadier General Bryan T. Roberts, the Commanding General of the U.S. Army Training Center and Fort Jackson, was being investigated for adultery and for being involved in a physical altercation. Roberts was suspended from his duties.

A rash of recent incidents — including an annual report showing increased sex assaults in the military, and two separate cases of men tasked with stemming sexual assault being charged with sexual assault — has critics, lawmakers, and even President Barack Obama focused on the problem.

Defense Secretary Chuck Hagel last week ordered all branches to “retrain, recredential and rescreen all sexual assault prevention and response personnel and military recruiters.”

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Slideshow: Tornadoes ravage Plains

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Destroyed vehicles lie in the rubble outside the Plaza Towers Elementary school in Moore, Okla., on Tuesday.

Launch slideshow

For many, it's impossible to view the heartbreaking stories coming out of Oklahoma and not feel an overwhelming urge to do something. But following your first impulse to help could just lead to more heartbreak, as many charitable givers often fall prey to scams in the wake of national tragedies.

Authorities are warning would-be donors to think carefully before they donate, and before they click.

"There is always a high probability for con-artists or 'travelers' to pop-up in the state following a storm, pushing quick-fix repair schemes and charity scams," Oklahoma Attorney General Scott Pruitt said in a press release. He urged Oklahomans to stay alert.

Scam artists crawl out of the woodwork only hours after the first pictures of death and destruction emerge. Like clockwork, spam emails, fake Facebook pages, telemarketing phone calls — even full-fledged websites that accept credit cards — pop up, all claiming falsely that they are collecting money for victims. Virus writers also get into the act, sending around booby-trapped emails that appear to come from charities, but are designed to invade victims' computers.

Pruitt said people around the country should donate to "reputable" organizations such as the Salvation Army or Red Cross. "The first scam we typically see after devastation like this is charity fraud,” he said

Pruitt also said his department has already sent 30 investigators into the tornado-ravaged area to stop local scams, fraud and price gouging.

For a detailed list of ways to help Oklahoma victims, visit NBC News' How to Help page.

Attorneys general in several other states, from Washington to South Carolina, have also issued charity fraud warnings.

Even consumers who wouldn't normally fall for scams are at risk in the aftermath of major disasters because the overwhelming sadness of the events, and the urgency of the need, can override a giver's natural sense of skepticism. The same urgency force is at play whenever a scam artist insists that a supposedly great deal is only available for a short time.

Federal Trade Commission spokesman Frank Dorman said he didn't believe his agency had received any complaints about Oklahoma-related scams yet, but that's not unusual: victims wouldn't yet realize they'd been scammed, he said.

The agency does offer an extensive set of tips for evaluating charities.

Consumers should beware anyone who:

• Uses high-pressure tactics like trying to get you to donate immediately, without giving you time to think about it and do your research.
• Refusing to provide detailed information about its identity, mission, costs and how the donation will be used.
• Won't provide proof that a contribution is tax deductible.
• Uses a name that closely resembles that of a better-known, reputable organization.
• Thanks you for a pledge you don’t remember making.
• Asks for donations in cash or asks you to wire money.
• Offers to send a courier or overnight delivery service to collect the donation immediately.

Follow Bob Sullivan on Facebook or Twitter. 

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MOORE, Okla. – On a soggy, miserable afternoon in Oklahoma, the search for survivors hit home.

Sgt. Jennifer Wehr has lived in the state for the last 10 years.

“Words can't describe everything we've been seeing right now,” she said.

The Army Reservist was one of about 200 soldiers and airmen from the Oklahoma National Guard that helped sift through the rubble Tuesday in the aftermath of the EF5 tornado that tore through Moore.

EF5 is the most severe level on the Enhanced Fujita scale that rates the strength of tornados and means the powerful storm is capable of lifting reinforced buildings off the ground and can hurl cars through the air.

“I just saw a family digging through a pile [and they] found their dog of five years,” Wehr said. “But unfortunately they found the dog didn't make it – and was buried by the house.”

By Wednesday, the mission had transitioned into search and recovery. No bodies and no survivors have been found since Monday. But search crews – including local firefighters, search teams from Texas and Tennessee and the Oklahoma National Guard – are still pacing neighborhoods.

Sgt. Mike Bell grew up in Oklahoma. He knows tornadoes well.

He was part of the search and rescue effort during the EF5 tornado that ripped through Oklahoma and Kansas on May 3, 1999. That twister killed 46 people in the two states, 36 people in Oklahoma City alone, and leveled many of the same communities – resulting in about $1 billion worth of damage.

But as far as Bell is concerned, “This is a thousand times worse. It’s like a war zone.” He added, “I was deployed to Katrina in 2005; that was bad. This is – words can't describe how bad this is.”

Like most National Guardsman, he has the added the difficulty of working in familiar territory.

“As an Oklahoman, it hurts,” he said. “I mean this is my state where I was born and raised.”

It’s not often an Army reservist chokes up during an interview, but Bell did so when discussing the children who died during the tornado.

He has two young kids of his own. “As a father of two young elementary students,” he paused as he choked up. “It hurts knowing that there were children lost.”

Army Reserve Spc. Brian Cannon lives in Moore, just blocks from where the tornado hit. He said he dodged the storm by hunkering down with family in a storm shelter.

“Being from Oklahoma you kind of get used to it,” he said. “But this was a lot more than we were used to.”

The reservists have their work cut out for them helping with the clean-up. The Oklahoma Insurance Department estimates the damage from Monday’s twister that stretched for more than 17 miles could top $2 billion in damages.

Related: 

• Littlest victims of Oklahoma tornado were 4 and 7 months old, state says
• Chaos and courage as tornado wrecks elementary schools
• Always smiling': First tornado victim identified
• 'The streets are just gone': Oklahoma rescue efforts continue

Sue Ogrocki / AP

A child is pulled from the rubble of the Plaza Towers Elementary School in Moore, Okla., and passed along to rescuers on May 20.

Rhonda Crosswhite, a sixth-grade math at Plaza Towers Elementary School in Moore, Okla., said the idea that school might be canceled Monday because of a looming tornado had never even crossed her mind.

“We never think that’s an option,” Crosswhite told NBC News. “We live in Oklahoma. Tornadoes happen all the time.”

The massive tornado that tore through Moore and killed 24 people bore down hard on Plaza Towers, where children sheltered inside from the roaring gusts, even as the building began to come apart around them.

The seven students who were killed at Plaza Towers, a single-story cinder block building that was leveled in the storm, were found dead in a pool of water, authorities said. Another student died at Briarwood Elementary, less than two miles away.

Richard Rowe / Reuters

Rescue workers look through the rubble at Plaza Towers Elementary School in Moore, Okla., on May 21, after a devastating tornado ripped through the town on May 20.

Tracy Stephan told NBC News that she went to Plaza Towers to pick up her daughter, who suffers from autism and epilepsy, before the tornado hit. She found the doors locked, with the tornado bearing down on her.

“Eventually after five minutes after not getting through, I turned back home and I decided to put my faith and trust in God the school was going to be OK,” the mother of three told NBC News. She ran back to the school after the twister passed, and found her daughter outside in the parking lot with other kindergartners.

“I grabbed her and wrapped her in my arms,” said Stephan.

Levi Hendricks also sped toward the school as the tornado took aim, to pick up his eleven-year-old granddaughter Kimberly. The fourth-grader meanwhile was crouched with some of her classmates in a bathroom and then a hallway.

After the tornado passed through, they found a way out of the demolished school.

“She was already out,” when he arrived at the school, Hendricks said. “They had an organized area where all the kids gathered at.”

Hendrick’s house, the back door of which once faced Plaza Towers’ busy playground, was flattened by the tornado.

“The playground was always full of kids, always even after school the kids all went up there and hung out because the playground was such a nice place for them to play at,” Hendricks said. “It was a nice family school. People who went there, now their kids are going there.”

In the aftermath of the storm, the First Baptist Church of Moore, about three and half miles from Plaza Towers, became a gathering place for students from all of the city’s schools who had not found their guardians, church spokesman Joey Dean said.

“We got word from the schools that they were going to bus all the kids who had not been picked up by their parents yet,” Dean said. Teachers and counselors shuttled over the students in their personal cars.

“Most them went home, and those who didn’t have homes, they spent the night,” Dean said.

Children in the city’s schools regularly prepare for the possibility of a tornado, district employees said.

“We have tornado and fire drills periodically throughout the year,” said Noah Minton, a psychologist for the Moore Public School district.

“They have drills, they have proposals they follow, but something this large, you get out of the way,” Minton said.

U.S. Representative Tom Cole, a resident of Moore, said on MSNBC that Plaza Towers was one of the most structurally sound buildings in the area.

“Yesterday our administrators, staff, teachers and students put our crisis plan into action immediately,” Moore Public Schools Superintendent Susan Pierce said at a press conference on Tuesday. “A tornado’s path is very unpredictable, but with little notice we implemented our tornado shelter procedures at every school site.”

City disaster plans and school documents show that officials had thought through what to do in the event of a tornado. They also suggest, however, that officials did not anticipate a disaster of this scale.

If a tornado came during the school day, teachers were instructed to have the students remain in their classrooms unless told to take them elsewhere, according to a cached version of the district’s 2012-2013 handbook for elementary school students and parents.

“Sudden tornadoes are a common occurrence in Oklahoma, especially in the spring of the year. Each of our schools has a tornado procedure, and the faculty and students have storm drills periodically,” the handbook reads. “If severe weather is rapidly approaching at the time of dismissal, students will be held at the school until the danger is passed. If there is a tornado warning but no immediate danger, school will be dismissed on schedule.”

The city of Moore does not have any community tornado shelters, according to the city’s department of emergency management website. The guidelines posted online also refer to the May 3, 1999 tornado outbreak that killed 36 others and injured 295 more.

“If we are struck again, it will very likely be by a much less intense storm,” the website says. “Sheltering in your residence – assuming it is a reasonably well-constructed home – is the best option.”

Hendricks said he thinks the instructions to shelter at Plaza Towers might have saved his granddaughter’s life.

“I do know there was a lot of lost lives, but I think there would have been a lot more if they let them out,” Hendricks said.

Related:

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• 'The streets are just gone': Oklahoma rescue efforts continue
• Officials: Grants to build 'safe rooms' delayed by red tape
• 'The school just started coming apart': Trapped students had nowhere to hide
• Full coverage of the Oklahoma tornado tragedy

Slideshow: Tornadoes ravage Plains

Ed Zurga / EPA

A monster tornado hit Moore, Okla., Monday afternoon, leaving at least 24 dead as the threat of further storms continues.

Launch slideshow

Tornado warnings were in effect all over the map on Tuesday, with areas from the Midwest to the Northeast being advised to take precautions during what was another day of wild and severe weather.

There were no significant tornado threats overnight, but parts of the country may be in danger of seeing twisters Wednesday afternoon, Weather Channel meteorologist Carl Parker said.  However it is unlikely that any potential tornadoes formed in the next 24 hours would be anywhere near the size of the one that ravaged Oklahoma on Monday, according to Parker.

Ohio and areas near the Great Lakes are most at risk of damaging wind gusts, large hail and tornadoes on Wednesday, according to The Weather Channel.

More from weather.com

It is better news than Tuesday, when 9.5 million people were in danger of experiencing "large and devastating" tornadoes as the deadly storm system moved east, forecasters warned.

And it was not just contained to Tornado Alley. Areas of western Massachusetts and Connecticut as well as eastern New York State also were issued tornado warnings Tuesday evening.

While many of these places have been experiencing strong winds and rain, none reported any twisters.

Tornado watches were in effect for portions of Arkansas, Mississippi, Louisiana, Missouri and Tennessee until 11 p.m. ET. Eastern Texas, central Louisiana and Mississippi were issued a severe thunderstorm warning going into Wednesday morning.

Severe rain and flooding caused havoc throughout the Dallas-Fort Worth area Tuesday afternoon. Area schools let out early and even the Dallas zoo closed to protect animals and visitors.

Weather Channel forecaster Bill Karins said the upcoming holiday weekend may provide some relief.

"An early look at Memorial Day weekend shows that most of the country should be quiet. The stormiest weather appears to be across the Plains and Midwest with scattered showers and thunderstorms," he said.

• Full coverage of the Oklahoma tornadoes from NBC News
• More news from weather.com

This story was originally published on Wed May 22, 2013 12:03 AM EDT

Slideshow: Tornadoes ravage Plains

Destroyed vehicles lie in the rubble outside the Plaza Towers Elementary school in Moore, Okla., on Tuesday.

Launch slideshow

As evening drew to a close in Oklahoma, after a day of tireless searching for survivors among the debris left behind by a powerful tornado, officials said the operation could end by nightfall Tuesday.

"We will be through every damaged piece of property in this city at least three times before we're done and we hope to be done by dark tonight," Moore Fire Chief Gary Bird said at a news conference.

Emergency crews and National Guard troops picked through neighborhoods without recognizable streets in a grim, house-by-house search of the blasted-out husk of a city left behind by the ferocious tornado.

Authorities lowered the death toll to 24, less than half the figure they gave in the initial chaos after the twister, but there was still no full accounting of those missing. Nine of the confirmed dead were children, including seven in a flattened elementary school.

Four bodies were recovered, including a 3-month-old baby, at a local 7-Eleven.

Working with search dogs and under menacing skies, the crews meticulously combed the rubble in the Oklahoma City suburb of Moore, which took a direct hit when the tornado cut a 17-mile path of destruction on Monday afternoon.

Dozens of people were pulled from the wreckage in the initial hours after the storm, but there were no reports of additional survivors found Tuesday — only scraps of wood, shreds of clothing, shards of glass and metal and cars crumpled into each other and into buildings. Entire stretches of Moore looked as if they had been put through a blender.

“I mean, there’s nothing,” said Robert Foster, whose family home was destroyed. “People are walking up and down the streets. It’s really upsetting to look at. We grew up there. That’s our whole childhood. And it’s all flattened now.”

Gov. Mary Fallin said there were 237 injured, but authorities cautioned that figure and the death toll could still rise. Even with the benefit of a full day’s light, people were only beginning to grasp the scope of the destruction in Moore and parts of Oklahoma City.

The Oklahoma University Medical Center admitted 59 children and 34 adults.

The National Weather Service said survey crews had found at least one area of Category EF5 damage — the highest classification for tornadoes, meaning winds had exceeded 200 mph.

Frank Keating, a former Oklahoma governor, said on MSNBC that as many as 20,000 families could be displaced.

“This was the storm of storms,” Oklahoma City Mayor Mick Cornett said.

The first of the victims was publicly identified — Ja’Nae Hornsby, a third-grader who was killed when the tornado demolished Plaza Towers Elementary School. She was remembered by her family Tuesday as full of joy and fond of playing dress-up. Her relatives gathered at a Baptist church in Oklahoma City to console each other.

A second victim, Hemant Bhonde, 65, became separated from his wife when the tornado struck their home, his family told NBC News. Bhonde's body was recovered Tuesday, hospital officials said. His wife survived.

Tannen Maury / EPA

Firefighters examine the rubble of a home in a destroyed neighborhood in Moore.

As they took the measure of what they had lost, people in Moore also marveled that they were alive, and began to share stories of survival and of how they protected each other when the twister struck, announcing itself with roaring wind.

Children from Plaza Towers Elementary School, where seven children were reported drowned in a pool of water, told of hearing sirens and running into a hall for cover, some still carrying their math books.

A teacher, Rhonda Crosswhite, said she huddled with students in a bathroom stall and draped herself over them for cover as the storm hit.

“One of my little boys, he just kept saying, ‘I love you, I love you, please don’t die with me, please don’t die with me,’” she told TODAY. “But we’re OK. And we made it out, and it finally stopped.”

She said all her students were accounted for.

Damian Britton, a fourth-grader, credited “Miss Crosswhite” with saving his life. He estimated it took about five minutes for the twister to pass through before the students emerged from cover to survey the damage and check on their classmates.

“It was just a disaster,’’ he said. “There was just a bunch of stuff thrown around and the cars were tipped over, and it smelled like gas.”

At an afternoon news conference, Bird said that search dogs were no longer “making any hits” at the school. He said no one had been found there Tuesday but cautioned that the search was still active.

“They will not declare that structure clear until they are down to the ground and have been through every piece of rubble in that building,” he said.

One child was killed at Briarwood Elementary School, elsewhere in Moore, said police Sgt. Jeremy Lewis. There was no word on how the ninth child died. Besides the 19 deaths in Moore, five were killed in southern neighborhoods of Oklahoma City.

Charlie Riedel / AP

Zac Woodcock salvages items from the rubble of a tornado-ravaged rental home in Moore.

Authorities said they hoped to have every home, business and car in Moore searched by nightfall. They worked under the threat of still more severe weather. Forecasters said parts of Oklahoma and Texas, including Dallas, were at risk for more tornadoes.

The tornado Monday spent 40 minutes on the ground, said Rick Smith of the National Weather Service.

“We’ve seen numerous structures that are wiped clean to the foundation,” he said.

Smith said that the first severe thunderstorm warning had gone out 44 minutes before the tornado touched down, and the first tornado warning 16 minutes ahead. The weather service said the storm, at its widest, stretched 1.3 miles.

President Barack Obama called it “one of the most destructive tornadoes in history.” Speaking from the White House, he pledged the full help of the federal government and said there was no time to waste.

“In an instant, neighborhoods were destroyed, dozens of people lost their lives, many more were injured, and among the victims were young children trying to take shelter in the safest place they knew, their school,” he said. “So our prayers are with the people of Oklahoma today.”

Fallin, after a helicopter tour that traced the tornado’s path, said searchers were having trouble because “the streets are just gone. The signs are just gone.”

Expressions of grief and support came from across the world. Pope Francis said on Twitter: “I am close to the families of all who died in the Oklahoma tornado, especially those who lost young children. Join me in praying for them.”

Queen Elizabeth II extended her deepest sympathies, and House Speaker John Boehner ordered flags at the Capitol to half-staff.

Relief efforts sprang up. The NBA’s Oklahoma City Thunder and its star player, Kevin Durant, each pledged $1 million. Others helped as they could: Miles from Moore, people went on Facebook to post family photos that had landed in their yards, hoping to match them with their owners.

Aerial pictures of the destruction brought to mind Joplin, the Missouri town virtually wiped off the map two years ago when an EF5 tornado killed 158 people and caused $2.8 billion in damage.

The twister cut a path similar to a tornado outbreak that ravaged Oklahoma and Kansas on May 3, 1999, killing 46 people and damaging or destroying more than 8,000 homes. Wind in that outbreak was clocked at 318 mph, the fastest ever recorded on earth.

Officials in Moore complained earlier this year about foot-dragging by the federal government over $2 million in federal grants for “safe rooms” in 800 homes to protect them from severe weather.

A spokesman for the Federal Emergency Management Agency told NBC News the agency was looking into the claim.

The city’s website also said, however, that Moore faced only a 1 to 2 percent chance of a tornado on any spring day, and that if a tornado did strike, there was less than a 1 percent chance that it would be as strong as the 1999 tornado.

Monday’s storm beat those odds. Alfredo Corrales and Viviana Lune rode it out in a shelter beneath their house. Corrales told TODAY that they had hunkered down there and heard voices above, and popped open the door to find several neighbors asking to come in.

The wind was so strong, Corrales said, that he and a neighbor had to hold the cellar door shut. When they emerged, they found a rewritten landscape.

“I saw basically nothing,” Luna said. “There were no fences there anymore, trees were snapped in half, roofs of houses were gone. Everything from people’s houses and even from neighborhoods across the street was laying in our yards. Half of the roof is torn off, the garage is caved in — it's just a total mess.”

More on the Oklahoma tornado:

How to help Oklahoma tornado victims

Tornado survivors: A 48-hour window of opportunity

‘The school started coming apart’: Trapped students had nowhere to hide

‘Bless you for posting’: Facebook group reunites tornado victims with photos, documents

Curse or coincidence? Scientists study Tornado Alley's past and future

NBC News' Jeff Black, Tracy Connor, Becky Bratu and Kristen Welker contributed to this report, as did NBC News contributor Alex Hannaford and The Associated Press.

This story was originally published on Tue May 21, 2013 8:55 PM EDT

Related:
'Major damage' as huge tornado slams Oklahoma

US Army

Army Brigadier General Bryan T. Roberts.

Army Brigadier General Bryan T. Roberts, the Commanding General of the U.S. Army Training Center and Fort Jackson, located in Fort Jackson, S.C., is being investigated for adultery and for being involved in a physical altercation, the Army announced Tuesday. Roberts has been suspended from his duties.

The altercation allegedly involved Roberts and an unidentified woman he is now being investigated for having an affair with, a U.S. military official told NBC News. The two were apparently involved in a recent argument. While making up, Roberts allegedly bit the woman’s lip, causing her to seek medical help.

The Command and Staff page on Fort Jackson’s website showed a vacant spot under Commanding General on Tuesday evening.

While the investigation is ongoing, Brig. Gen. Peggy Combs, Commandant of the U.S. Army Chemical, Biological, Radiological and Nuclear School at Fort Leonard Wood, Missouri, will serve as the interim commander.

jackson.army.mil

A screen shot shows Fort Jackson's senior leadership. The commanding general is notably no longer included on the page.