MCCOMB, Mississippi: New Orleans' flood defenses appeared to withstand Hurricane Isaac, but thousands of people to the north and south of the city had to be evacuated or rescued as the storm edged inland from the U.S. Gulf Coast with whistling winds and constant rain. At least two deaths were reported.
"Hopefully, as far as the city of New Orleans is concerned, the worst is behind us," New Orleans Mayor Mitch Landrieu said Thursday.
But the storm flooded neighborhoods in a rural part of the state and in neighboring Mississippi, and it left nearly half of Louisiana without power. The waters continued to rise, even as Isaac, now a tropical storm, meandered northward Thursday toward neighboring Arkansas.
The floodwaters "were shockingly fast-rising, from what I understand from talking to people," Lt. Gov. Jay Dardenne said. "It caught everybody by surprise." Many residents had assumed they could ride out Isaac, a lowest-category hurricane.
Louisiana officials on Thursday ordered the evacuation of low-lying, sparsely populated areas as a dam on the Tangipahoa River was in danger of failing. Officials feared the swollen river would flood areas near the border with Mississippi, but Mississippi officials said they didn't think the volume of water would threaten communities. Louisiana Gov. Bobby Jindal said officials would release water at the dam.
President Barack Obama declared federal emergencies in both states, according to a statement from the White House, freeing up federal aid for affected areas.
Along the shores of Lake Ponchartrain just north of New Orleans, officials sent scores of vehicles to help evacuate about 3,000 people as rising waters lapped against houses. Floodwaters rose waist-high in some neighborhoods, and authorities worked to rescue people stranded in their homes.
Isaac arrived exactly seven years after the devastating Hurricane Katrina and passed slightly to the west of New Orleans, where the city's newly fortified levee system, helped by $14 billion in federal repairs, easily handled the assault. But low-lying areas outside the city were swamped.
"Hurricane Isaac has reinforced for us once again just how vulnerable these critical areas are," Democratic U.S. Sen. Mary Landrieu said.
One person was reported killed in New Orleans, compared with 1,800 deaths from Katrina in Louisiana and Mississippi. And police reported few problems with looting. Landrieu ordered a dusk-to-dawn curfew.
A man was killed Thursday morning when a tree fell on his truck in Mississippi. Authorities said Isaac was causing heavy rain and strong winds at the time. They did not release the man's name.
In Plaquemines Parish, a sparsely populated area south of the city that is outside the improved federal levee system, dozens of people were stranded in flooded coastal areas and had to be rescued. The storm pushed water over an 18-mile (29-kilometer) levee and put so much pressure on it that authorities planned to intentionally puncture the floodwall to relieve the strain.
By midafternoon Wednesday, Isaac had been downgraded to a tropical storm and the Louisiana National Guard ceased rescue operations in Plaquemines Parish, saying it felt confident it had gotten everyone out. There were no serious injuries.
Officials rushed to evacuate more than 100 nursing home residents. In this mostly rural parish, even the sick and elderly are hardened storm veterans.
"I don't think we had to evacuate to begin with," said Romaine Dahl, 59, as he sat in a wheelchair. "The weather was a hell of a lot worse last night than it is now."
By early Thursday, Isaac's maximum sustained winds had decreased to 45 mph (72 kph) and the National Hurricane Center said it was expected to become a tropical depression by Thursday night, meaning its top sustained winds would drop below 39 mph (63 kph).
Forecasters expected Isaac to move farther inland over the next several days, dumping rain on drought-stricken states across the nation's midsection before finally breaking up over the weekend.
Because Isaac's coiled bands of rain and wind were moving at only 5 mph (8 kph) - about the pace of a brisk walk - the threat of storm surges and flooding was expected to linger Thursday.
The storm knocked out power to 901,000 homes in Louisiana and more than 150,000 customers in neighboring Mississippi, stripped branches off trees and flattened fields of sugar cane so completely that they looked as if a tank had driven over them.
In coastal Mississippi, officials used small motorboats Wednesday to rescue at least two dozen people from a neighborhood flooded in Pearlington.
Back in New Orleans, the storm canceled remembrance ceremonies for those killed by Katrina.
As hard wind and heavy rain pelted Melba Leggett-Barnes' home in the Lower 9th Ward, an area leveled during Katrina, she felt more secure than she did seven years ago.
"I have a hurricane house this time," said Barnes, who has been living in her newly rebuilt home since 2008.