As I recall, they had known for at least three days that Katrina was going to be very, very bad.
In that time, using school buses and any Greyhound buses in the area, they could have moved at least three hundred thousand residents in an orderly fashion.
The city officials simply were beyond simple incompetence.
Yes, the city leaders were incompetent.
Three days before Katrina hit and the levees failed, Katrina was a small storm in the Gulf with a cone of probability reaching from Texas to the
SW coast of Florida.
And the bottom line is that those people who did not evacuate, did not want to evacuate.