As residents add up the damage from Isaac's nonstop rain, a half a million are still living without power. NBC's Gabe Gutierrez reports.
Updated at 8:30 p.m. ET: Hundreds of thousands of people in Louisiana on Friday suffered in humid heat due to power outages caused by Isaac, while tornado alerts were issued for five other states as the system moved slowly into the central U.S.
By Friday evening, four tornadoes were reported in southwest Illinois and one in Missouri, all with minimal damage. Watches were also issued for parts of Arkansas, Kentucky, Missouri and Tennessee.
In Louisiana, Republican presidential nominee Mitt Romney toured the New Orleans area, saying he wanted to understand the extent of devastation and "obviously to draw some attention ... so that people around the country know that people down here need help."
The White House earlier announced that President Barack Obama will tour damaged Louisiana areas on Monday. Jindal said he invited the president and that the head of the Federal Emergency Management Agency had already visited.
A man, forced to abandon his sailboat during Tropical Storm Isaac, is now trying to find the vessel. WPMI's Darwin Singleton reports.
"We're not talking politics," Jindal, a Republican, said at an Isaac briefing Friday. "We're thrilled to have both these leaders here."
Isaac crawled into the nation's midsection Friday, leaving a soggy mess along the Louisiana and Mississippi coasts.
It will be a few days before the soupy brown water recedes and people forced out of flooded neighborhoods can return home.
And the damage may not be done. Up to 50,000 people in Tangipahoa Parish were given an evacuation order Thursday when water from Isaac -- which by late afternoon had weakened to a tropical depression -- threatened to overwhelm a dam across the state line in Mississippi.
By late Thursday, the Percy Quin State Park dam, located about 100 miles north of New Orleans, was no longer an imminent threat, dam safety engineer Dusty Myers said.
Connie Uddo was devastated when her home was devoured by Katrina, but she faced the damage head-on by establishing a volunteer organization to help people rebuild. Now that same nonprofit is helping Isaac's victims. NBC's Kate Snow reports.
Crews worked into the night to repair the dam and earlier created a slow release of water to ease pressure on the earthen structure.
The storm caused anywhere from $700 million to $2 billion in insured onshore losses, disaster modeler AIR Worldwide said late Thursday. That would still leave Isaac well outside the 10 most costly U.S. hurricanes.
New Orleans' Audubon Park recorded 18.7 inches of rain in a 24-hour period -- exceeding all records dating back to 1871, said Jeff Masters of Weather Underground. Many other locations in Louisiana and Mississippi logged more than 10 inches of rain.
In Arkansas, power lines were downed and trees knocked over as Isaac moved north into the state.
Slidell, a town of about 27,000 people northeast of New Orleans, took the brunt of a storm surge from Lake Pontchartrain, which left some neighborhoods under about a foot of water.
NBC's Thanh Truong reports from Louisiana where Hurricane Isaac knocked out power to many portions of the state's Gulf Coast.
"You'd have never made me believe a Category 1 would dump this much water," said Sam Caruso, 71, a former mayor of Slidell who toured the town in his pickup truck on Thursday.
As the flood waters rose, some residents, including Caruso, wondered whether the new federal levee system had shored up New Orleans at the expense of low-lying neighboring parishes outside the system's protection - a debate that is likely to continue.
New Orleans, spared any major damage, lifted its night curfew and returned to its usual liveliness, although it was dampened by heavy humidity.
"I have a battery-operated fan. This is the only thing keeping me going," said Rhyn Pate, a food services worker who sat under the eaves of a porch with other renters on Thursday, making the best of the circumstances. "And a fly swatter to keep the bugs off me — and the most important thing, insect repellent."
Following scores of rescues, widespread flooding and forced evacuations, officials recovered at least two bodies in the wake of Hurricane Isaac. Meanwhile, large parts of Louisiana remain underwater. NBC's Gabe Gutierrez reports.
The heat was getting to Marguerite Boudreaux, 85, in Gretna, a suburb of New Orleans.
"I have a daughter who is an invalid and then my husband is 90 years old, so he's slowing down a lot," she said, red in the face as she stood in the doorway of her house, damp and musky from the lack of air conditioning.
National Guardsmen rescued or escorted more than 3,000 residents, Gov. Jindal said Friday, and more than 1,000 people had to be rescued by boat or high-water vehicles. Some 5,000 people were still in Louisiana shelters Friday.
At least six deaths were attributed to Isaac. A man in Slidell, La., drowned after driving into a ditch where the water was 9 feet deep Thursday night. Two bodies were found inside a flooded home overnight in hard-hit Plaquemines Parish south of New Orleans, officials said overnight. And a Mississippi tow-truck driver was killed when a tree fell on his vehicle, a tree fell on a woman in Waveland, Miss., and a Louisiana man died after falling from a tree as he tried to help a friend.
Isaac hit on the seventh anniversary of Katrina, a hurricane that devastated New Orleans and left more than 1,800 dead.
A downgraded Isaac floods coastal communities and forces new evacuations, but levees still hold.
The two storms had little in common. Katrina came ashore as a Category 3 storm, while Isaac was a Category 1 at its peak. Katrina barreled into the state and quickly moved through. Isaac lingered across the landscape at less than 10 mph and wobbled constantly. Because of its sluggishness, Isaac dumped copious amounts of rain. Many people said more water inundated their homes during this storm than during Katrina.
Both storms, however, caused the Mississippi River to flow backward. And both prompted criticism of government officials.
In the case of Isaac, officials' calls for evacuations so long after the storm made landfall caused some consternation.
Jefferson Parish Council President Chris Roberts said forecasters at the National Hurricane Center in Miami need a new way of measuring the danger that goes beyond wind speed.
"The risk that a public official has is, people say, 'Aw, it's a Category 1 storm, and you guys are out there calling for mandatory evacuations,'" Roberts said.
Eric Blake, a specialist at the hurricane center, said that although Isaac's cone shifted west as it zigzagged toward the Gulf Coast, forecasters accurately predicted its path, intensity and rainfall. He did say the storm came ashore somewhat slower than anticipated.
Blake cautioned against using Katrina as a benchmark for flooding during other storms.
"Every hurricane is different," Blake said. "If you're trying to use the last hurricane to gauge your storm surge risk, it's very dangerous."
Some residents in Slidell, Louisiana are contending with several feet of water from Tropical Storm Isaac.
Also Thursday, in southeast Louisiana's Plaquemines Parish, which is outside the federal levee system protecting New Orleans,crews intentionally breached a levee that was strained by Isaac's floodwaters.
In Louisiana alone, the storm cut power to 901,000 homes and businesses, or about 47 percent of the state. That was down to about 30 percent Friday.
Entergy Corp., Louisiana's largest power company, said Isaac knocked out power to nearly 770,000 of its customers in Louisiana, Mississippi and Arkansas. Only three storms have left more customers without power: Hurricanes Katrina (1.1 million), Gustav (964,000) and Rita (800,000), the company said in a news release.
More than 15,000 utility workers began restoring power to customers in Louisiana and Mississippi, but officials said it would be at least two days before power was fully restored.
In Mississippi, several coastal communities struggled with all the extra water, including Pascagoula, where a large portion of the city flooded and water blocked downtown intersections.
High water also prevented more than 800 people from returning to their homes in Bay St. Louis, a coastal Mississippi town that lost most of its business district to Katrina's storm surge.
Isaac killed at least 23 people in Haiti and the Dominican Republic before taking aim at the United States.
The Associated Press and Reuters contributed to this report.
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