Bill Haber, Associated Press A woman wades through floodwaters coated with a fine layer of oil yesterday in flooded downtown New Orleans. Click photo for larger image.

NEW ORLEANS -- The city that has prided itself on letting the good times roll found itself overwhelmed yesterday by the hardships caused by Hurricane Katrina.

Failing levees and pumps allowed surging waters to flood more than 80 percent of the city that, in the best of times, has lived a charmed existence below sea level and fought off the danger of a deluge from the Mississippi River. Food and drinkable water were scarce, forcing city officials to order nonessential people to evacuate. By afternoon, officials were ordering rescue shelters to be evacuated.

The fabric of civil order was frayed. The Superdome changed from an arena of sports heroics into a grim experience for thousands of refugees. Three hospital patients died in the dome, and another death was reported by officials. One suicide was reported but could not be independently confirmed.

A massive pool of water, so contaminated with gasoline and chemicals that it looked blood-red under the blazing sun, seeped into the city and swept across the central business district. Water gurgled from every drain, splashed in waves against marble stairs of banks and transported the flotsam of a shattered city.

Water spilled from several breaches in the city's protective levees, including the critical levee next to the 17th Street Canal, at the edge of Lake Pontchartrain. Mayor C. Ray Nagin estimated that the breach was two or three city blocks wide.

Officials' immediate concern was attempting to block the breach with sandbags. After that, the focus was to be on the failed pumps that typically move water out of the city. Even when they are all functional, Nagin said, they can reduce the water level in the city by only an inch or an inch and a half per hour.

	Bill Feig, Associated Press Two breeches in the Florida Street levee allow water from the Mississippi River to pour into New Orleans. Click photo for larger image.

"We're talking about a long time before the water subsides," Nagin said.

Meanwhile, the waters continued to rise.

"The water is coming from the river. The water is coming from the lake. The water is coming from the canals. And it's meeting up right here. It's getting higher and higher, and nobody knows when it's going to stop," said Paul Williams, 43, who was wading through the city's 7th Ward in an attempt to reunite with his parents and his 2-year-old son, who were trapped there.

"There's hope here," Williams said. "But not much."

On Monday, Hurricane Katrina dealt this city a glancing blow but made landfall nearby. Winds of more than 100 mph lashed the city, broke windows and caused many streets to flood.

Early yesterday morning, a wave of storm-related surging water rushed through the levees, canals and pumps that protect this low-lying port. Two levees broke, allowing the waters to invade.

"We probably have 80 percent of our city underwater; with some sections of our city, the water is as deep as 20 feet. Both airports are under water," Nagin told a radio interviewer.

Thousands of refugees who thought they had weathered the worst of the storm abandoned their houses and waded to high ground yesterday, often through chest-high water. On Loyola Avenue, family after family spilled out of working-class neighborhoods and housing projects in East New Orleans.

	Matt Rourke, Austin American-Statesman via AP Refugees in search of a safe haven wade along Canal Street in New Orleans. Click photo for larger image.

Part of the new exodus from eastern pockets of the city began when a rumor circulated that engineers were going to be forced to destroy a levee to relieve water pressure -- a rumor that did not appear to be true, although officials said they were considering having to cut into some levees.

If it happened, it would send another wave of water coursing through the 9th Ward, where Robert Esco, 41, fled with his family. It took him, his wife and two children three hours to walk from their home to the central business district. Esco was trying to make it to a hospital, where he assumed his family would be allowed to sleep on the floor.

"I didn't think it would be like this," Esco said. "I never thought I'd see this in all my days."

Yesterday afternoon Nagin ordered everyone still in the city -- including police officers not considered "central emergency personnel" -- to leave. But almost all the evacuation routes were blocked by flooding and debris.

The twin spans of Interstate 10 -- the main artery in and out of town to the east -- were washed out in parts and seriously damaged, officials said. Mark Lambert, a spokesman for the state Department of Transportation and Development, estimated that about 40 percent of the eight-mile-long bridge was washed out by the storm.

It could be weeks before the interstate reopens. To the west, the interstate was impassable where it crosses Lake Pontchartrain, because of high water. The causeway over the lake was inaccessible.

	Michael Ainsworth, Dallas Morning News via AP Evacuees attempting to escape rising waters try to leave New Orleans on the Interstate 10 bridge yesterday. Click photo for larger image.

That left a tortuous route over the Mississippi River and through side streets as the only way in or out of the city -- but even that route could soon be closed, authorities warned.

Those who tried to escape by car did not get far. Cars were strewn about, abandoned in rising water.

The National Guard planted trucks at the end of the flooded zone and carried people to shelter. Many families were split up, because there were limited numbers of seats in the trucks.

"I don't want to lose you!" Terrell Washington, 26, yelled to his wife and child after they were loaded into the back of a camouflaged truck.

As the water neared the heart of the French Quarter, some hotels began evacuating, ordering residents to leave.

Houses that were not damaged by wind began to collapse as the standing water eroded their structures, particularly along the shore of Lake Pontchartrain.

Nagin said electricity would be off in the bulk of New Orleans for at least a month. There was no estimate of when the city's drinking water might be potable. A major water main was shattered.

At least 300 rescue boats were deployed in the New Orleans area, said Bo Boeringer, spokesman for the state Department of Wildlife and Fisheries. The boats were forced to maneuver around unusual underwater obstructions such as street signs and fences, he said.

It was unclear how many people remained stranded in attics and on roofs, but as time passes, they were likely losing battery power in their cell phones, Boeringer said.

Thousands of people remained unaccounted for last night.

"There are still bodies floating," Nagin said.

At the Superdome, a generator blew out and its backup showed signs of faltering, officials said. The Federal Emergency Management Agency was considering whether to airlift thousands of people to another city, probably Baton Rouge.