Last Updated 2:44 p.m. ET
(CBS/AP) NEW ORLEANS - The storm that was Hurricane Isaac - and which is now a tropical depression - swirled into the central U.S. Friday, leaving behind a darkened, soggy mess in Louisiana. Neighborhoods were underwater, and even homes that stayed dry didn't have lights, air conditioning or clean water.
There's still significant flooding along the Gulf Coast, and thousands of people are in shelters this morning, said CBS News correspondent Byron Pitts. .
New Orleans broke an all-time rainfall record, getting more than 18 inches in 24 hours - and more rain is headed north toward the Midwest.
The remnants of Isaac are slowly crossing Arkansas, downing power lines and trees. Forecasters say an additional 2 to 4 inches of rain is possible as Isaac heads into Missouri. The National Weather Service issued flash flood warnings for parts of Arkansas, Jefferson and Lincoln Counties in Ark.
Isaac has lost strength since coming ashore late Tuesday as a Category 1 hurricane, but it's still expected to provide a dousing for much of the nation's midsection - from Arkansas north to Missouri and into a corner of Iowa, then east through Illinois and Indiana to Ohio - in coming days. Rainfall totals could reach up to 7 inches, according to a U.S. Drought Monitor weekly update Thursday.
The storm cut power to early half the homes and businesses in Louisiana. On Friday afternoon 632,000 customers were still without power, the Public Service Commission said. In neighboring Mississippi, utility companies said they are working to restore power to more than 150,000 customers in south and central parts of the state.
On Friday Entergy said 10,000 customers in Arkansas are also without electricity because of Isaac. Entergy - which serves customers in Arkansas, Louisiana, Mississippi and Texas - says Isaac has been the utility's fourth-largest storm in terms of power outages.
This is the first morning without bad weather in this region since Monday. That means the work crews can pick up the pace today restoring electricity. More than 15,000 utility workers are at work in Louisiana and Mississippi, but officials said it would be at least two days before power is fully restored.
At least six deaths in Louisiana and Mississippi were blamed on the storm.
It will be a few days before the soupy brown water recedes and people in flooded areas can return home. New Orleans itself was largely spared, thanks in large part to a levee system fortified after Katrina devastated the Gulf Coast in 2005.
In hard-hit Plaquemines Parish, officials confirmed the deaths of a man and woman who were found in a home in Braithwaite.
A 75-year-old Slidell man apparently drowned when his SUV ran off a flooded interstate on-ramp and plunged into a ditch where the water was about 9 feet deep Thursday evening, Louisiana State Police said.
Other fatalities included an unidentified man who died in a restaurant blaze in Gretna that firefighters could not control because of Isaac's strong winds Wednesday. Another man died falling from a tree during the storm, and a tow truck driver in Mississippi was killed when a tree crushed the cab of his truck.
Crews intentionally breached a levee that was strained by Isaac's floodwaters. In three days, the slow-moving storm dumped more than 20 inches of rain on this stretch of the Gulf Coast, submerging entire neighborhoods, taking down trees and power lines. At one point, more than 700,000 households and businesses lost electricity.CBS Affiliate WWL reports Plaquemines Parish officials intend to cut as many as ten openings in a levee Friday to drain water from the soaked parish.
Parish President Billy Nungesser said the process is somewhat complicated: The equipment has to stay by the breaches to patch them when the tide rolls in, and to open them up again once the tide rolls out again.
Nungesser said the parish did a similar thing after Hurricane Gustav, but added Isaac presents more of a challenge. "This was three times the water that was in Gustav," he said.
Republican presidential nominee Mitt Romney was headed to Louisiana to tour the damage. Romney scheduled a last-minute visit Friday to Lafitte, La., with Gov. Bobby Jindal. Lafitte was the site of rescue efforts when Isaac's tidal surge pushed in through the night Wednesday and into Thursday.
White House spokesman Jay Carney announced that President Barack Obama would also visit the state on Monday to examine water and wind damage from Isaac.
Much of Isaac's destructive power fell hard on rural communities and small towns. While some are pledging to rebuild, others plan to leave for good.
"We're going to try to get a rental car wherever we stop at and go to Georgia," one woman said. "I'm not coming back. I can't take no more hurricanes, I can't."