The death toll from Hurricane Katrina could reach into the thousands in New Orleans alone, the mayor of the stricken city warned last night.
As army engineers battled to plug the city's breached levees, and a huge operation was under way to evacuate 25,000 of the homeless to Houston in Texas, Mayor Ray Nagin issued a stark warning of the scale of the unfolding disaster.
"We know there is a significant number of dead bodies in the water," and others were dead in attics, the mayor said. Asked how many, he said: "Minimum, hundreds. Most likely, thousands."
The mayor added that there will be a "total evacuation of the city . . . the city will not be functional for two or three months".
Around 80 per cent of New Orleans remained under water as emergency workers warned of the dangers posed by the dead bodies of people and animal carcases, spilled chemicals and oil that floated through the deserted streets.
Louisiana governor Kathleen Blanco said the situation was desperate and there was no choice but to clear out. "The logistical problems are impossible and we have to evacuate people in shelters," the governor said.
"It's becoming untenable. There's no power. It's getting more difficult to get food and water supplies in, just basic essentials." The Pentagon began mounting one of the largest search and rescue operations in US history. Four US navy ships were sent to the Gulf coast with supplies of fresh drinking water and other emergency equipment.
The devastated area is facing twin threats of fast-rising water and looters. The first threat was being fought with every method available from helicopter drops of giant sandbags to plans to float a barge into a 152 metre-wide (500ft) hole in a floodwall.
The looting provoked fury from state officials appalled that people were using the disaster as a cover for looting rifles from gun stores, jewels from the tourist shops in New Orleans's French Quarter and money from abandoned one-armed bandits left in the wrecked floating casinos of Biloxi farther up the coast.
President George Bush is to visit the area shortly, having headed back from his ranch to be behind his White House desk. He has declared Katrina to be an "incident of national significance", a designation that frees additional aid.