Discuss as:

A state-by-state look at superstorm Sandy's impact

Hurricane expert Bryan Norcross reports from the Weather Channel headquarters on Sandy's slow-moving churn toward the Northeast, where portions of the East Coast are under siege. Ten states are under a state of emergency, and hundreds of thousands of homes lost power so far during the slow-moving storm.

New York
On Monday evening, the New York City mayor's office issued a direct tweet to its residents: "New Yorkers: Stay inside. Do not go outside. Being outside is incredibly dangerous."

Another directive told residents to stay away from windows as the water level at Battery Park, at Manhattan's southern tip, reached 13.5 feet, surpassing the previous record of 11.2 feet in 1821.

Parts of lower Manhattan flooded as water poured into the Brooklyn-Battery and Queens Midtown tunnels, bursting into a subway station and even cascading into the construction site at Ground Zero.

Floodwater is now receding following significant flooding in the lower Manhattan area of New York City, blocks from the World Trade Center site. WNBC's Ida Siegal reports.

Nearly six million people were without electricity Monday, and officials warned they could remain without power for days. The storm lashed the region with furious winds, blinding rain and flooding. A mandatory evacuation of more than 375,000 people in low-lying parts of New York City was issued shortly after the entire transit system was brought to a slow, grinding halt on Sunday.

Lucas Jackson / Reuters

After strong winds and heavy rain washed out bridges and damaged homes in multiple countries, the hurricane looks toward the northeastern U.S.

Sandy flooding begins, 'only going to get worse'

The New York Stock Exchange and other U.S. financial markets shut down for Monday and Tuesday and thousands of flights were canceled at the city's major airports. New York power company Con Edison shut off power to part of lower Manhattan to allow for quicker restoration after the storm passes.

“Don’t be fooled, don’t look out the window and think it doesn’t look so bad," New York Gov. Andrew Cuomo said Monday.

The New York University Langone Medical Center moved about 215 critical care patients to other hospitals because its backup generator was out, the hospital said.

Gov. Chris Christie said Monday rescue boats are ready to be deployed if needed. More than 300,000 residents in New Jersey are without power, and in Atlantic City the water continues to rise. WCAU's Chris Cato reports.

New Jersey
Sandy made landfall near Atlantic City on Monday evening, washing away part of its storied boardwalk. The storm surge also went over the sea wall in Cape May with high tide early in the morning and punched through dunes in other communities, NBCNewYork.com reported. The state's barrier islands were under an evacuation order, along with Atlantic City, but many people stayed behind.

Gov. Chris Christie said they would have to wait until morning to be rescued. "I hope, I pray, that there won't be any loss of life because of it," he said.

See readers’ storm images: share yours, if you can do so safely

Police have sealed off Point Pleasant Beach in New Jersey, and a mandatory evacuation order is in effect. There are fears that Hurricane Sandy could wipe out entire sections of the town. NBC's Ron Allen reports.

Connecticut

Flooding trapped thousands of residents in coastal communities, and wind gusts toppled trees across the state, leaving more than half a million homes and businesses in the dark, NBCConnecticut.com reported.

Gov. Dannel Malloy called the state's coastal flooding "the worst water event in the state's history" and urged residents in the hardest-hit areas to stay put and ride out the storm through the night.

"Do not leave a dwelling to get into the water to swim" or try to drive away, Malloy warned in a late-evening press conference. "Stay where you are, move to a higher level."

One person died in Mansfield after being pinned by a tree, NBCConnecticut.com reported.

View complete coverage from NBCConnecticut.com

John Minchillo / AP

Transportation shuts down and streets empty in preparation for Hurricane Sandy.

Delaware
Water covered some major roads on Monday, and residents scrambled to prepare for a week of misery. Hundreds of people fled to shelters as rough surf pounded the coast. On Sunday, Delaware Governor Jack Markell ordered the evacuation of 50,000 coastal residents as the storm threatened to bring up to 12 inches of rain, winds of up to 80 mph and a wall of water as high as 11 feet.  

Hugh Phillips, 69, and his wife, Martha, were among the first to leave their home in the Long Neck area of Sussex County, an area prone to flooding. “We were told to get the heck out,” Hugh Phillips told The Associated Press. “I was going to stay, but it's better to be safe than sorry.”

Washington, D.C.
The region’s entire public transit system was suspended Monday, the largest mass shutdown in the city since Hurricane Isabelle in 2003. Schools, colleges and universities also closed their doors in anticipation of power outages and dangerous road conditions. Some extended their closures into Tuesday and Wednesday. Winds in the city were blowing from about 20 to 36 mph and officials expected them to get stronger later in the day. Washington-area utility providers warned residents to prepare for power outages that could last for weeks.

Also, Sandy rained on a D.C. tradition: The city's 26th annual High Heel Race was rescheduled due to the weather.

Pennsylvania
Authorities said a Berks County man was killed when he was hit by a falling tree outside his home Monday, NBC10 in Philadelphia reported. By late Monday, more than 11 inches of rain had fallen in some parts, with lots more on the way. At one point, winds in Philadelphia hit 68 mph. Waves reached 12 feet in Delaware Bay on Monday, and 21 feet near Toms River.

"We are still facing some very severe conditions overnight," Philadelphia Mayor Michael Nutter said.

The city can expect winds between 40 mph and 50 mph, another couple inches of rain, near-record flooding along the Delaware River, and more power outages, Nutter said.

Maine
Officials predict coastal flooding and beach erosion, and utility crews have been brought in from Canada to handle anticipated power failures. Many Mainers hustled with their worst-case scenario preparations, scooping up generators, flashlights and bottles of water. Many schools and universities closed.

But some residents on Maine's islands took a wait-and-see approach. “They’ll pretty much stay in denial until they see it arrive,” Al Bleau, head of Peaks Island's Community Emergency Response Team, told the Bangor Daily News. “They see all these big storms that form and then nothing happens (locally)."

Hurricane expert Bryan Norcross reports from the Weather Channel headquarters on Sandy's slow-moving churn toward the Northeast, where portions of the East Coast are under siege. Ten states are under a state of emergency, and hundreds of thousands of homes lost power so far during the slow-moving storm.

Rhode Island
Rhode Island Gov. Lincoln Chafee urged residents to "make the decision now" to evacuate from coastal and low-lying areas ahead of the storm. Chafee toured coastal areas of Rhode Island, including Narragansett, and early Monday afternoon urged people to consider evacuating before the storm worsens. A decision to shut down highways, including Interstate 95, was under consideration, the governor said. Several hundred members of the Rhode Island National Guard were on standby, ready to provide support to municipalities, NBC 10 in Providence reported.

North Carolina 
Two U.S. Coast Guard helicopters rescued 14 crew members that had abandoned the HMS Bounty, a tall ship built for a 1962 movie, about 90 miles off the coast. But another crew member was found dead and the captain was missing. Those rescued were flown to Air Station Elizabeth City in North Carolina where they were met by emergency medical services personnel, the Coast Guard said. The storm lashed barrier islands and rendered several homes and businesses nearly inaccessible.

Vermont
Sandy's approach comes less than 14 months after the state was devastated by Tropical Storm Irene, the most significant natural disaster to hit the state in almost a century, according to The Associated Press. Gov. Peter Shumlin declared a state of emergency to provide access to National Guard troops. The University of Vermont canceled classes. People were starting to report power outages and damage, according to Vermont Public Radio. Red Cross officials were preparing to open shelters as needed. The storm was expected to start affecting southern Vermont Monday afternoon, with potentially hurricane-force winds starting later in the day, according to local media reports.

“At this point we do feel that we are adequately prepared,” Public Safety Commissioner Keith Flynn in Waterbury told The Burlington Free Press. “We’ve really focused on our outreach to the public this time."

Massachusetts
More than 172,000 people were without power, Boston.com reported. The Massachusetts Bay Transportation Authority shut down all subway, bus and commuter rail service at 2 p.m. on Monday. In Cape Cod, huge waves crashed and flooded Chatham Fish Pier, where winds were clocked as high as 62 mph, according to WHDH-TV.

Maryland
Maryland's governor urged people to stay off the roads for the next 36 hours because of the threat of flooding.

"Don’t put yourselves or your families in jeopardy, or your first responders," said Gov. Martin O'Malley, WBAL-TV in Baltimore reported. "This will be unlike any storm we've had to weather."

Maryland Lieutenant Governor Anthony Brown talks with MSNBC's Chris Jansing about flooding and other issues facing the state in the wake of the storm.

The storm’s presence was felt in Deep Creek Lake in Garrett County, where snow was falling due to a cold front moving in from the west. 

As of 5 p.m. Monday, more than 46,600 Baltimore Gas and Electric Company customers were without power. That number was expected to rise sharply. 

Virginia
The worst coastal flooding appears to be over, but a lot of rain and wind are still to come, the Richmond Times-Dispatch reported. Power blackouts are likely still to come and officials warned that almost 1 million could ultimately lose electricity. A high tide and storm surge Monday flooded streets and yards throughout coastal areas of the state, but there were no reports of injuries or major damages.

“This really is a strange storm," Virginia Gov. Bob McDonnell said on MSNBC’s Morning Joe. “We’ve got coastal flooding, tropical storm and hurricane-force winds at the coast, eight to 10 inches of rain at the coast and then in Southwest Virginia we have blizzard warnings, up to a foot or two feet of snow.”

Still, some Virginians seem unaffected by the storm.

“I’m just sitting back watching TV and hoping the electricity doesn’t go out,” Lonnie Moore of Tangier Island, Va., told the Times-Dispatch.

West Virginia
Highway crews on Monday began what could be a week of snow removal in some areas, as forecasters predicted up to three feet of snowfall, the Charleston Gazette reported. Forecasters also expanded a blizzard warning Monday to at least 14 counties and predicted wind gusts approaching 50 miles per hour after 4 p.m. The Weather Channel's winter expert Tom Niziol said higher elevations could see 18-24 inches of snow.

The highest ridges of the central Appalachians could get two feet of snow and six inches of snow could fall on the coal fields in southern West Virginia, according to NOAA.

Most West Virginians live in lower level areas, however, and would not likely be impacted by the heavy snowfall, The Associated Press reported.

New Hampshire

Gov. John Lynch declared a state of emergency, urging motorists off the roads on Monday. He also directed non-essential state workers to be released early from work. The governor placed 100 New Hampshire Guard soldiers on active duty.

Ohio
Rain and wind gusts of up to 60 miles per hour were felt Monday and could blow through the Columbus area over night, the Columbus Dispatch reported. The National Weather Service issued a high-wind warning for much of central Ohio beginning at noon Monday and running through 6 p.m. Tuesday. Forecasters were predicting the worst weather conditions between 8 p.m. Monday and 8 a.m. Tuesday. They also said the light rain could change to a snow mix by midnight with light accumulation possible. Residents of low-lying areas and along Lake Erie were also warned to watch for flooding.  

Michigan
Some 800 miles away from the coast, the National Weather Service issued a flood advisory for one county and a high wind advisory for a 14-county region, the Michigan News reported. Forecasters cautioned that winds could reach 40 to 50 miles per hour.

Tennessee
The first snowfall of the season was likely to pound areas of the state, the National Weather Service predicted. There were already four inches of snow on the ground in areas of the Great Smoky Mountains Monday, and forecasters said the higher elevations in eastern Tennessee could get up to 17 inches of snow before the storm subsides Wednesday, the News Sentinel reported. Additionally, flights to Nashville International Airport were being cancelled Monday.

NBCNews.com's Andrew Mach and Sevil Omer contributed to this report.

More content from NBCNews.com:

Follow US news from NBCNews.com on Twitter and Facebook