Steve H1, if you are talking about New Orleans, there are an estimated 100,000+ people still in the city. About a quarter of them are in the Superdome. The mayor of NO was offering some advice to those still in the French Quarter. He said try to get the 3rd floor of a 3 story building, and take something to break through the roof in case the water gets that high. I'd say there's a good chance an awful lot of people could die.

Also, some of the parishes around New Orleans are reporting that only about 80% of the people evacuated. Some of those parishes aren't in much better shape to weather a Cat 5.