Counting the dead: Recovery workers have started removing and counting the dead in New Orleans after engineers began pumping water out of the flooded city. President George Bush will head an investigation into what went wrong with relief efforts, although he said there is "ample time" for such an inquiry.
The city's mayor, Ray Nagin, warned of horrific scenes ahead once the water has been pumped out to reveal a toxic stew of mud, decomposing bodies and chemical waste. "It's going to be awful and it's going to wake the nation up again," he said.
Predicting that the death toll could reach 10,000, the mayor continued to urge everybody still in the city to leave. He said there should be no strong-arm tactics used to remove residents but warned that drinking water would no longer be distributed to those who insisted on staying.
"We have to convince them to leave. It's not safe here. There is toxic waste in the water and dead bodies and mosquitoes and gas. We are pumping about a million dollars' worth of gas a day in the air. Fires have been started and we don't have running water."
Thousands of paratroopers are using small boats to rescue those still stranded in central districts.
Lieut Gen Russel Honore, who heads the US army operation in the city, said New Orleans is now secure and denied that criminal gangs had impeded the rescue operation in recent days. Soldiers and police are patrolling every part of the city, and a curfew is in operation from 7pm daily.
An inquiry into what went wrong in New Orleans is likely to look at how government agencies prepared for the hurricane, the inadequacy of the evacuation plan and the slow pace of the rescue operation.
Public criticism has focused on the Federal Emergency Management Agency (Fema) for excessive bureaucracy in responding to the disaster.
Louisiana state officials have accused Fema officers of turning back two truckloads of water sent to New Orleans by WalMart and of failing to co-operate with state and local authorities. The Bush administration has sought to deflect blame towards Louisiana and New Orleans authorities.
Those evacuated from New Orleans may have to spend months in makeshift accommodation. Many have been left without banking and benefits documents, but Fema is issuing them with a debit card to buy essential goods.