Intentional breach weighed as Isaac batters La.

Research students from the University of Alabama measure wind speeds as Hurricane Isaac hits New Orleans Aug. 29, 2012. AP Photo

Updated at 3:42 p.m. ET

(CBS/AP) NEW ORLEANS - Louisiana officials said Wednesday they may have to intentionally breach a levee in a flooded area as Isaac made a slow, drenching slog inland from the Gulf of Mexico and the first death was tied to the hurricane that was downgraded to a tropical storm.

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

The move comes as Plaquemines Parish President Billy Nungesser told reporters that a levee breach caused flooding measured between 12 feet and 14 feet on the east bank of the Mississippi River.

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 25 people were still reportedly awaiting rescue on the parish's east bank on rooftops and in attics.

(Watch at left)

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.

The extent of the damage was not entirely clear because officials did not want to send emergency crews into harm's way.

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.

The National Weather Service downgraded Isaac to a tropical storm Wednesday afternoon when its maximum sustained winds fell to 70 miles per hour.

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.

"When this is over, I think we need to check the wind speeds because I lost a good portion of my roof, my fence is down, and water is blowing through the sockets in my house from the back wall," Nungesser said in a phone call to WWL-TV. "That only happened in Katrina."

Plaquemines Parish resident Gene Oddo called WWL-TV while riding out the storm with his wife and baby girl in their attic Wednesday morning in Braithwaite. He said the water level was up to his house's doorframe.

(Watch at left)

"The water came up so quick," Oddo told WWL-TV. "It looks like we lost everything. If I have to, I may have to shoot a hole in my attic here to get out on our roof, but it looks like the water's not coming up anymore."

Oddo said authorities told him about storm surge going over the levee around 2 a.m.

"The threat was for flood, which I knew that, and I'd rather be here to save what I can because the insurance doesn't cover all that much," Oddo said.

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Meanwhile in New Orleans, Mayor Mitch Landrieu issued a curfew for the city as Isaac lashed the city on the seven-year anniversary of Hurricane Katrina's destructive arrival.

Police cars had been patrolling the nearly empty streets since Isaac began bringing fierce winds and heavy rains to the city Tuesday night. The curfew was set to start Wednesday night and would last until further notice.

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.

"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."

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