I assume it's much the same way in most big cities. The apple is rotting from the inside out. Unless something is done, it will just move out from the center.
This is a very well documented trend, from an academic context. I'm a criminal justice major, and I've read study upon study about this very topic. I find it very interesting.
Its a cyclical trend. Affluent areas of a city's downtown gradually become crime infested low income areas, so the people with the means move to the suburbs. Over time, the suburban property values decline due to age, so the low income folks move to the suburbs in hope of a better environment. At that time, the affluent folks move back into downtown areas, which usually sparks "revitalization projects" such as high priced apartments, high rise condos, renovation of homes in old historic neighborhoods, etc. And the cycle starts all over again.
This is just a guess, but I'd bet that in future studies, it will show that the mass emigration of NOLA residents to other major metro areas will disturb this cycle, and cause affluent residents to totally relocate out of both the city and the surrounding suburbs. This will leave entire cities, and to some degree the suburbs, as ghettos simultaneously.
