Concerns grow as the rank floodwaters in the swamped city of New Orleans pose extra risk. Officials braced for what could be a staggering death toll by readying 25,000 body bags.
Across miles of ravaged neighborhoods of clapboard houses, grand estates and housing projects, workers struggled to find corpses and persuade the city's last stubborn residents to leave.
Coast Guard Vice Adm. Thad Allen, just appointed as deputy to FEMA Director Michael Brown, said it was unsafe to be in New Orleans.
"We're starting an operation today going block by block through the city, requesting people to leave their homes," he said on CBS' "The Early Show." "We need everyone out so we can continue with the work of restoring this city."
Government tests confirmed that the floodwaters are thick with sewage-related bacteria in amounts at least 10 times higher than acceptable safety limits. The muck is believed to contain E. coli, certain viruses and a type of cholera-like bacteria.
The danger of infection was not limited to the New Orleans area. The bacteria are feared to have migrated to crowded shelters outside the state, where many evacuees are staying. Four deaths - one in Texas, three in Mississippi - have been attributed to infected wounds, the AP reports.