The mayor of New Orleans has reversed course, halting a plan to bring residents back to parts of the city, and asking those already there to leave.  Another severe storm could be on the way, and the fear is that floodwaters could rise once again.

A new Orleans resident is stopped at a checkpoint outside the city

Just hours after some New Orleans residents began returning home for the first time in weeks, Mayor Ray Nagin told them to turn around and leave. The mayor on Monday suspended his plan to start repopulating up to one-third of the city, as more severe weather approached.

"Our levee system is still in a very weak condition,” said Mayer Nagin. ”Our pumping stations are not at full capacity and any type of storm that heads this way and hits us could put the east bank of New Orleans Parish in very significant harm's way."

Mayor Ray Nagin

Tropical Storm Rita may be tracking toward New Orleans, at a time when the protective levees breached during Hurricane Katrina still need reinforcement.

U.S. President George W. Bush also addressed the situation. "If it were to rain a lot, there is concern from the Army Corps of Engineers that the levees might break. And so, therefore, we're cautious about encouraging people to return."

Earlier in the day President Bush had criticized the mayor's plan to bring people back.  Federal officials were concerned about the lack of drinking water and emergency services.

"The mayor, you know, he's got this dream about having a city up and running, and we share that dream,” said the president. “But we also want to be realistic about some of the hurdles and obstacles that we all confront in repopulating New Orleans."

After three weeks away from home, this resident wants to see what is left of her possesions

Even as he suspended the resettlement effort, Mayor Nagin defended his original decision to reopen parts of the city.

"I felt it was important for our residents to come back to the city and to feel like they had a city to come back to."

And for some homesick residents, even a brief visit did bring peace of mind.

One resident said, "I wanted to come back to see what I can save and what I can't save."

The mayor said everyone in the city should be prepared to evacuate by Wednesday.  About 20 percent of New Orleans remains flooded three weeks after Katrina, and crews are still conducting a house-to-house search for the dead.