NEW ORLEANS -

Isaac, which has been downgraded to a tropical storm from a hurricane, plodded its way across Louisiana on the seventh anniversary of Katrina, with officials weighing whether to bust a hole in a levee to relieve some of the water that was spilling over a wall in a rural part of the state Wednesday.

Louisiana Gov. Bobby Jindal said officials may cut a hole in a levee on the east bank of Plaquemines Parish to relieve pressure on the structure. At a news conference in Baton Rouge, Jindal said there was no estimate on when that might occur.

He said as many as 40 people are reportedly in need of rescue in the area.

Plaquemines Parish has also ordered a mandatory evacuation for the west bank of the Mississippi River below Belle Chasse, worried about a storm surge. The order affects about 3,000 people in the area, including a nursing home with 112 residents.

Officials said the evacuation was ordered out of concern that more storm surge from Isaac would be pushed into the area and levees might be overtopped.

Joshua Brockhaus, an electrician who lives in the flooded area, helped rescue neighbors in his boat.

"I'm getting text messages from all over asking for help," he said. "I'm dropping my dogs off and I'm going back out there."

The hurricane's impact was a surprise for him.

"We didn't think it was going to be like that," he said. "The storm stayed over the top of us. For Katrina, we got 8 inches of water. Now we have 13 feet."

Alvin Sylve, a disabled former long-distance truck driver, was preparing to evacuate. He lived on street with rows of doube- and single-wide trailers in Jesuit Bend in Plaquemines Parish, an area outside the federal levee system where people were ordered to evacuate Wednesday as conditions worsened.

"We've never seen it this bad," he said. "The way this wind is shifting."

He was hunkering down at a friend's double-wide with leaks springing in the ceiling.

"This double-wide is shaking, even though it's anchored down. You see another piece came off the roof," he said, pointing to a flying piece of roof tile. "It's falling apart!"

In Vermilion Parish, Sheriff Mike Couvillon said a 36-year-old man had gone to help two friends move a vehicle from under a tree to prepare for Isaac on Tuesday evening, and fell to his death after climbing 18 feet up a tree. Deputies don't know why the man climbed the tree.

Rescuers in boats and trucks plucked a handful of people who became stranded by floodwaters in thinly populated areas of southeast Louisiana. Authorities feared many more could need help after a night of slashing rain and fierce winds that knocked out power to more than 600,000 households and businesses.

Although Isaac was much weaker than Katrina, which crippled the city in 2005, the threat of dangerous storm surges and flooding from heavy rain was expected to last all day and into the night as the immense comma-shaped storm crawled across Louisiana.

Army Corps spokeswoman Rachel Rodi said the city's bigger, stronger levees were withstanding the assault.

"The system is performing as intended, as we expected," she said. "We don't see any issues with the hurricane system at this point."

There were initial problems with pumps not working at the 17th Street Canal, the site of a breach on the day Katrina struck, but those pumps had been fixed, Rodi said.

In Plaquemines Parish, a fishing community south of New Orleans, about two dozen people who stayed behind despite evacuation orders needed to be rescued.

Clyde Jones stayed behind and ended up regretting it.

"Stayed in the attic," he said. "Fortunately, I brought a chainsaw with me yesterday in case it happened. I cut a hole in the attic to get out, made a few phone calls and somebody came and picked us up."

It took rescuers almost three hours to reach Jones and his family.

National Guard troops, dive teams and private boaters worked to rescue dozens of people. Firefighters used axes to cut hole in roofs.

All the people who were rescued in that area were taken to a temporary shelter at the St. Bernard Parish Jail.

"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."

As Isaac's eye Isaac passed overhead, authorities in armored vehicles saved a family whose roof was ripped off, Larpenter said.

Two police officers had to be rescued by boat after their car became stuck. Rescuers were waiting for the strong winds to die down before moving out to search for other people.

"The winds are too strong and the rain too strong," Plaquemines Parish spokeswoman Caitlin Campbell said.

Water driven by the large and powerful storm flooded over an 18-mile stretch of one levee in Plaquemines Parish. The levee, one of many across the low-lying coastal zone, is not part of the new defenses constructed in New Orleans after Katrina.