National Guard trucks haul residents through floodwaters to the Superdome after Hurricane Katrina hit in New Orleans

Louisiana's governor says all remaining people need to be evacuated from New Orleans because of continued flooding a day after Hurricane Katrina devastated the southern U.S. Gulf Coast, causing catastrophic damage and mounting death tolls.

Kathleen Blanco says people huddled in rescue centers need to be taken out of the city. She called the situation heartbreaking and said some neighborhoods will have to be completely rebuilt.

Ms. Blanco added that it could be a long time before power is restored to New Orleans, which is 80 percent underwater. Looting broke out across the city Tuesday.

Authorities say the Army Corps of Engineers is working on a plan to plug a 100-meter-long break in the levee. Authorities are currently dropping massive sandbags on the area.

Officials say they have no death toll yet as rescuers concentrate on finding survivors stranded in the floodwaters. In the Mississippi coastal city of Biloxi, officials say Monday's 9-meter storm surge may possibly have killed hundreds. Biloxi Mayor A.J. Hollaway called Katrina "our tsunami."

Authorities are continuing emergency rescue efforts in Louisiana, Alabama and Mississippi. They say almost two million people are without electricity in the affected areas.