NEW ORLEANS — Isaac poured unrelenting rain Thursday, flooding areas north and south of New Orleans even as the city's fortified defenses held and forcing officials to launch speedy evacuation and rescue efforts in the face of fast-rising waters.
Along the shores of Lake Ponchartrain, near New Orleans, officials sent scores of buses and dozens of high-water vehicles to help evacuate about 3,000 people as rising waters lapped against houses and left cars stranded. Floodwaters rose waist-high in some neighborhoods, and the Louisiana National Guard was working with sheriff's deputies to rescue people stranded in their homes.
Even as Isaac weakened on its slow trek inland, it continued to spin off life-threatening weather including storm surges, inland flooding from torrential rain and potential tornadoes. Nearly half of Louisiana electrical customers lost power and another 150,000 were out in neighboring Mississippi.
A Coast Guard helicopter hoisted a couple and their dogs early Thursday from a home in LaPlace, between the Mississippi River and Lake Ponchartrain, after storm surge poured into their neighborhood and local authorities called for help. The couple was taken to New Orleans and reported in good condition.
"The husband and wife and their two dogs were in an area where a lot of houses washed away," said Lt. Cmdr. Jorge Porto. "They used a flashlight inside the house as a signaling device, which made all the difference in locating them effectively."
The floodwaters "were shockingly fast-rising, from what I understand from talking to people," Lt. Gov. Jay Dardenne said. "It caught everybody by surprise."
A tow truck driver was killed Thursday morning when a tree fell on his truck in Picayune, Miss., just across the state line from Louisiana. Authorities said Isaac was causing heavy rain and strong winds at the time. They did not release the man's name.
President Barack Obama declared federal emergencies in Louisiana and Mississippi late Wednesday, allowing federal aid to be freed up for affected areas.
Isaac arrived seven years after Hurricane Katrina and passed slightly to the west of New Orleans, where the city's fortified levee system easily handled the assault.
"Unfortunately, that's not been the case for low-lying areas outside the federal system, in particular lower Jefferson and Plaquemines parishes," said Louisiana Democratic U.S. Sen. Mary Landrieu. "Hurricane Isaac has reinforced for us once again just how vulnerable these critical areas are. We must re-engage the Corps of Engineers on this."
Jerry Larpenter, sheriff in nearby Terrebonne Parish, said he thinks the storm's impact took many by surprise.
"I think a lot of people were caught with their pants down," he said. "This storm was never predicted right since it entered the Gulf. It was supposed to go to Florida, Panama City, Biloxi, New Orleans. We hope it loses its punch once it comes in all the way."
Louisiana's Public Service Commission said 901,000 homes and businesses around the state — about 47 percent of all customers — were without power Thursday. Utility company Entergy said that included about 157,000 in New Orleans.
New Orleans' biggest problems seemed to be downed power lines, scattered tree limbs and minor flooding. One person was reported killed, compared with 1,800 deaths from Katrina in Louisiana and Mississippi. And police reported few problems with looting. New Orleans Mayor Mitch Landrieu ordered a dusk-to-dawn curfew.
But in Plaquemines Parish, a sparsely populated area south of the city that is outside the 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 levee and put so much pressure on it that authorities planned to intentionally puncture the floodwall to relieve the strain.
Officials rushed to evacuate more than 100 nursing home residents from Plaquemines Parish, an area with a reputation for residents hunkering down to weather storms and perhaps the hardest hit by Isaac. In this hardscrabble, 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. And I got an idea that after all this is said and done they're going to say everything is over with, go on back home."