American cities have been destroyed before through acts of nature and accidents.
They've always been rebuilt.
But in rebuilding there's a choice to make.
1: Put in a combined effort of private, institutional, corporate, and governmental groups to rebuild bigger and better than it was before. When the City of Chicago burned in 1871, this was the approach. What came before - dangerous buildings designed with no thought given to the risks of fire - simply wasn't good enough. The future was safe buildings, new parks, skyscrapers, a world's fair, and status, until the rise of Los Angeles, as the 2nd biggest city in the US.
2: Waste time and money by engaging in political wrangling, bitching about someone else's lack of leadership, questioning if rebuilding is even worth it, and (finally) watching in wonder as a nearby city takes preeminance over yours. This was Galveston after the storm of 1900. Before 1900, Galveston was bigger and richer than Houston. Today, Houston is the 4th largest city in the US with a population of nearly 2 million people; Galveston? A small, poor coastal city with around 55,000 inhabitants.
So which is better? Which choice do you want for New Orleans? I personally want '1' for the people of New Orleans. But too many people seem to be unaware that the choice is there and that they are, wholly ignorant of what they are doing, getting themselves into '2'.