High winds propelled by Hurricane Rita are causing a storm surge in New Orleans, with water levels whipped up above the height of the already damaged defences.
At least a foot of water is now pouring through the Lower Ninth Ward area, which had only just been pumped dry following the flooding after Katrina.
Colonel Richard Wagenaar, US Army Corp of Engineers, said: "The water's come up to a much higher elevation than we thought it would this early in the storm.
"We were expecting a storm surge of two to five feet tomorrow morning - and right now in places we've got six feet."
