This is a pretty ridiculous Law suit, I mean how can they prove that. Hurricanes have occured throughout all of recorded history and they built New Orleans in a basin, those people were just stupid who did not leave, if anything those people should be sued for not leaving and wasting governement funds. It is sad that so much distruction came from nature, but thats just what it is NATURE and we can't really control NATURE.
Actually, ATV, it is partially the people's fault who did not leave, but a lot of the blame can be laid at the feet of the local and state government, both for ineffective evacuation and for slow response. Mayor Nagin had hundreds of school buses he could have used to ferry people out of town, but they ended up underwater because his office wouldn't allow them to be used for this purpose. Gov. Blanco didn't declare a state of emergency until well after the storm hit, which means the state couldn't request assistance from FEMA, which prohibited, by law, any action from FEMA.
Had they done their jobs, the loss of life would have been lower and recovery work begun sooner. For evidence, I point to the response to Hurricane Gustav(IIRC), that, while not as powerful as Katrina, hit NO more directly, but caused a much lower death toll, if any, and little flooding.