NEW ORLEANS -- The Army Corps of Engineers raced to patch New Orleans' fractured levee system Tuesday and residents were forced to decide yet again whether to stay or go as a new, rapidly strengthening hurricane threatened to flood the city anew.
"First it was come back, then it was go," said Karen Torre, who returned to her home Tuesday to clear debris before leaving again. "We're just trying to do what they tell us and get a few things done in between."
The new threat was Hurricane Rita, which strengthened into a 105-mph Category 2 storm as it barreled into the Gulf of Mexico.
Forecasters said the storm could strengthen to a 131-mph-plus Category 4 and hit Texas by the weekend. But a slight turn to the right was possible, and engineers warned that even a glancing blow to the city and as little as three inches of rain could swamp the city's levees.
"The protection is very tenuous at best," said Dave Wurtzel, the Army Corps official responsible for repairing the 17th Street Canal levee, whose huge breach during Katrina caused the worst of the floods that wrecked the city.
Mayor Ray Nagin and Louisiana Gov. Kathleen Blanco strongly urged people along the Louisiana coast to be prepared to get out. The federal government's top official in the city, Coast Guard Vice Adm. Thad Allen, said the preparations in and around New Orleans included 500 buses for evacuation, and enough water and military meals for 500,000 people.
"We are praying that the hurricane dissipates or that it weakens," said Blanco, who declared a state of emergency. "This state can barely stand what happened to it."
In anticipation of another hurricane, the Corps drove a massive metal barrier across the 17th Street Canal bed to prevent a storm surge from Lake Pontchartrain from swamping New Orleans again. Although engineers have left a large opening in the wall to allow floodwater to continue to be pumped back into the lake, it will have to be closed quickly if Rita or another storm threatens.
Government engineers and private contractors also worked around the clock across New Orleans to repair the damage to the system of pumps, concrete floodwalls, earthen berms and canals that protect the below-sea-level city.
In addition, the corps had 800 giant sandbags weighing 6,000 to 15,000 pounds on hand just in case, and ordered 2,500 more to shore up low spots and plug any new breaches. It was also putting pumps and other materials where they might be needed.
"If New Orleans was directly affected by a Category 1, I would be concerned -- I would pull my people out," said David Pezza, the top geotechnical engineer for the Army Corps. "These levees are greatly compromised."
Rita's threat to the levees already forced the mayor to suspend the phased reopening of the city and order a new round of evacuations. In some areas where bars, restaurants and shops were opening their doors for the first time since Hurricane Katrina, people were boarding up windows and getting ready to leave town again.
"I'm worried about getting more rain," Frank Wills said as he packed up to leave his 150-year-old Creole cottage in uptown New Orleans. "The ground's saturated, and a lot of the storm drains are clogged up with garbage. If we get much at all, I think you'll see flooding where you never saw it before."
Even residents who have already been evacuated once faced the prospect of being uprooted again. At the Cajun Dome in Lafayette, emergency officials arranged to take the 1,000 refugees from the New Orleans area out on buses if Rita tracks north.
"Nobody here even wants to hear the word 'hurricane' right now," said Carlette Ragas, who has not been back to her home on Plaquemines Parish, south of New Orleans, since Katrina and has already enrolled her children, ages 11 and 7, in a Lafayette-area school.
The call for another evacuation of New Orleans came after repeated warnings from top federal officials, including President Bush, that the city was not yet safe because of the lack of full electricity, drinkable water and 911 emergency service.
Nagin ordered residents who had slipped back into still-closed parts of the city to leave immediately. He also urged everyone already settled back into Algiers, the only neighborhood now open to returning residents, to be ready to evacuate as early as Wednesday.
Nagin said two busloads of evacuees left from a staging area at the convention center Tuesday afternoon. He estimated that 400 to 500 residents were left in the city. The city decided to allow people to continue cleanup until dusk Tuesday and will start to re-enforce the evacuation order Wednesday, he said. He did not give specifics on how the order will be enforced.
To people who refuse to leave, Nagin had this message: "We're all adults. We really don't want to take people out by gunpoint. We hope they see the threat ... and obey the law."
If Rita does affect the city, Blanco promised the emergency response would be well-coordinated. "Now obviously that's a lot easier this time" because emergency workers already are in the area, she said.
President Bush made his fifth trip to the Hurricane Katrina zone on Tuesday to meet with local business and political leaders in Gulfport, Miss., and received a briefing in New Orleans on preparations for Hurricane Rita.
Bush also appeared with Nagin amid tensions between the mayor and Allen over who is in charge, and conflicting information on whether people should come or go. At one point this week, Nagin said Allen apparently regarded himself as "the new crowned federal mayor of New Orleans."
At a news conference later Tuesday, all appeared forgiven. "We may not always agree, but we have one mission, and that is to bring New Orleans back," Nagin said as he hugged the admiral and presented him with a "I (heart) N.O." T-shirt.
The process of recovering bodies and searching for survivors continued Tuesday, and in one house in the Mid-City neighborhood, they found both.
Rescue workers said John and Leola Lyons, both 72, stayed together through Katrina's howling winds and floods that filled their one-story house with 18 inches of water. Even after she died, he stayed.
Federal agents finally broke down the door and found them, three weeks and a day after the storm. John Lyons was whisked off to a hospital, a recovery team was dispatched to collect his wife's remains.
"We have half a happy ending," said emergency medical technician Christopher Keller. "That's pretty good these days."
Associated Press Writers Mary Foster and Cain Burdeau in New Orleans, Brett Martel in Lafayette, La., and Stacey Plaisance in Baton Rouge, La., contributed to this report.