Let me comment on that,
First: The area in N.O. that was proned for flodding is a poor district, meaning alot people who if made the decision to evacuate, couldn't because they were unable, due to the fact that no one own a car to transport them out of the city.

Secondly:
We are not planners, so we should not make judgements on what and when city officials make the decsion to evacuate. I agree with you, that heed the warning was issued along time ago. I believe it would cost the city of N.O. a ton of money to evacuate all the citizens out of town. Money that the city did not have.

Third and Last:
We as citizens of this great Nation of ours need to behind them now. They need each and everyone of us regardless of what and when things were ordered. I believe in the coming months and years, this will be a lessons learned for all. Hopefully, the next one will be years, and years away. Maybe never.