Updated 3:28 a.m. ET
(CBS/AP) NEW ORLEANS - Hurricane Isaac sidestepped New Orleans on Wednesday, sending the worst of its howling wind and heavy rain into a cluster of rural fishing villages that had few defenses against the slow-moving storm that could bring days of unending rain.
Isaac arrived exactly 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.
According to a National Weather Service advisory issued at 2:00 a.m. ET on Thursday morning, Isaac had top sustained winds of 50 mph, and was moving northwest at 5 mph.
The city's biggest problems seemed to be downed power lines, scattered tree limbs and minor flooding. Just one person was reported killed, compared with 1,800 deaths from Katrina in Louisiana and Mississippi. And police reported few problems with looting. Mayor Mitch Landrieu ordered a dusk-to-dawn curfew just to be sure.
President Obama signed declarations of disaster in Louisiana and Mississippi and has authorized federal aid to help those states impacted by Isaac, according to statements issued by the White House on Wednesday.
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.
Earlier, Louisiana Gov. Bobby Jindal said as many as 40 people are reportedly in need of rescue in the area. CBS affiliate WWL-TV reports that 75 people were rescued from flooded homes and rooftops from Braithwaite, La., and that dozens people were still reportedly awaiting rescue on the parish's east bank on rooftops and in attics..
By midafternoon, Isaac had been downgraded to a tropical storm and the Louisiana National Guard wrapped up rescue operations in Plaquemines Parish, saying they felt confident they had gotten everyone out and there were no serious injuries.
"That should be everyone," National Guard spokesman Capt. Lance Cagnolatti said. "We're pulling out."
Even at its strongest, Isaac was far weaker than Hurricane Katrina, which crippled New Orleans in 2005. Because Isaac's coiled bands of rain and wind were moving at only 5 mph -- about the pace of a brisk walk -- the threat of storm surges and flooding was expected to last into a second night as the immense comma-shaped system crawled across Louisiana.
"We didn't think it was going to be like that," Brockhaus said. "The storm stayed over the top of us. For Katrina, we got 8 inches of water. Now we have 13 feet."
In Plaquemines Parish, about two dozen people who defied evacuation orders needed to be rescued. The stranded included two police officers whose car became stuck.
"I think a lot of people were caught with their pants down," said Jerry Larpenter, sheriff in nearby Terrebonne Parish. "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."
At left, watch video of a levee in Plaquemines Parish being overtopped as filmed by storm chaser Jeff Piotrowski
The storm knocked out power to as many as 700,000 people, stripped branches off trees and flattened fields of sugar cane so completely that they looked as if a tank had driven over them.
Plaquemines Parish ordered a mandatory evacuation for the west bank of the Mississippi below Belle Chasse because of worries about a storm surge. The order affected about 3,000 people, including a nursing home with 112 residents. In Jefferson Parish, the sheriff ordered a dusk-to-dawn curfew.
After wind-driven water spilled over the levee in Plaquemines Parish, state officials said they would cut a hole in it as soon as weather allowed and equipment could be brought to the site.
In coastal Mississippi, wildlife officers used small motorboats Wednesday to rescue at least two dozen people from a neighborhood Isaac flooded in Pearlington.
Back in New Orleans, the storm canceled remembrance ceremonies for those killed by Katrina. Since that catastrophe, the city's levee system has been bolstered by $14 billion in federal repairs and improvements. The bigger, stronger levees were tested for the first time by Hurricane Gustav in 2008.
Army Corps of Engineers spokeswoman Rachel Rodi said the flood-control measures were working "as intended" during Isaac.
"We don't see any issues with the hurricane system at this point," she said.
Isaac came ashore late Tuesday as a Category 1 hurricane, with 80 mph winds near the mouth of the Mississippi River. It drove a wall of water nearly 11 feet high inland.
In Vermilion Parish, a 36-year-old man died after falling 18 feet from a tree while helping friends move a vehicle ahead of the storm. Deputies did not know why he climbed the tree.
The storm stalled for several hours before resuming a slow trek inland, and forecasters said that was in keeping with its erratic history. The slow motion over land means Isaac could be a major soaker, dumping up to 20 inches of rain in some areas. But every system is different.
"It's totally up to the storm," said Ken Graham, chief meteorologist at the National Weather Service in Slidell, La.
Slashing rain and wind gusts up to 100 mph buffeted New Orleans skyscrapers.
In the French Quarter near Bourbon Street, Jimmy Maiuri was shooting video from outside his second-floor apartment. Maiuri, who fled from Katrina at the last minute, stayed behind this time with no regrets. He was amazed at the storm's timing.
"It's definitely not one to take lightly, but it's not Katrina," he said. "No one is going to forget Aug. 29, forever. Not here at least."
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. She and her husband, Baxter Barnes, were among the first to get a home through Brad Pitt's Make It Right program.
Her yellow house with a large porch and iron trellis was taking a beating but holding strong.
"I don't have power, but I'm all right," said Barnes, a cafeteria worker for the New Orleans school system.
In Mississippi, some sections of the main highway that runs along the Gulf, U.S. 90, were closed by flooding.
In Pass Christian, a Mississippi coastal community wiped out by hurricanes Camille and Katrina, Mayor Chipper McDermott was optimistic that Isaac would not deal a heavy blow.
"It's not too bad, but the whole coast is going to be a mess," he said.
Forecasters expected Isaac to move inland over the next several days, dumping rain on drought-stricken states across the nation's midsection before finally breaking up over the weekend.