NEW ORLEANS — A week after Hurricane Katrina, engineers plugged the levee break that swamped much of the city and floodwaters began to recede, but along with the good news came the mayor's direst prediction yet: As many as 10,000 dead.

Sheets of metal and repeated helicopter drops of 3,000-pound sandbags along the 17th Street canal leading to Lake Pontchartrain succeeded Monday in plugging a 200-foot-wide gap, and water was being pumped from the canal back into the lake. State officials and the U.S. Army Corps of Engineers say once the canal level is drawn down 2 feet, Pumping Station 6 can begin pumping water out of the bowl-shaped city.

Some parts of the city already showed slipping floodwaters as the repair neared completion, with the low-lying Ninth Ward dropping more than a foot. In downtown New Orleans, some streets were merely wet rather than swamped.

"We're starting to make the kind of progress that I kind of expected earlier," New Orleans Mayor Ray Nagin said about the work on the break, which opened at the height of the hurricane and flooded 80 percent of the city up to 20 feet deep.

The news came as many of the 460,000 residents of suburban Jefferson Parish waited in a line of cars that stretched for miles to briefly see their flooded homes and to scoop up soaked wedding pictures, baby shoes and other cherished mementoes.

"A lot of these people built these houses anticipating some floodwater, but nobody imagined this," sobbed Diane Dempsey, a 59-year-old retired Army lieutenant colonel who could get no closer than the water line a mile from her Metairie home. "I'm going to pay someone to get me back there, anything I have to do."

"I won't be getting inside today unless I get some scuba gear," added Jack Rabito, a 61-year-old bar owner who waited for a ride to visit his one-story home that had water lapping to the gutters.

Katharine Dastugue was overjoyed to find that floodwaters had gone across her lawn but stopped just inches from her doorstep. As she stood waiting for a boat to take her in, she made a list of thing she hoped to salvage before being forced to leave again Wednesday.

"If I can just get my kids' baby photos," she said. "You can't replace those."

In New Orleans, Nagin upticked his estimate of the probable death toll in his city from merely thousands, telling NBC's "Today" show, "It wouldn't be unreasonable to have 10,000."

As law enforcement officers and even bands of civilians — including actor Sean Penn — launched door-to-door searches of the city for survivors, they were running up against a familiar obstacle: People who had been trapped more than a week in damaged homes yet refused to leave.