I'm inclined to agree with Publius that racism isn't what killed people in No Man's Land. Those people were casualties in a class war. They couldn't get out because the paycheck or government check goes out on the first day of the month and the storm hit on the last day, when their bank accounts were tapped out.
(Tangential question: What's the logic of sending every government check on the same day? Why not send them out to 1/4 of the people every week, or something?)
The best predictor of someone's future success is how successful his/her parents were. Better than race, better than education. Of course, race is well correlated with income, and that traces back to a few centuries of slavery followed by a century of intense economic repression based on race. Mediocre income mobility mixed with historical racism means that the consequences of that racism are persistent well after the imposition of race neutral practices.
The people stuck in No Man's Land were poor and black. They were there because they were poor. Some were poor because of historical racism, others because they were sick, or old, or whatever. This is a serious problem in America. If No Man's Land makes us all appreciate the important consequences of poverty in America a little bit better, I suppose that's a small benefit.
Speaking of class warfare, suspending the policy of paying the prevailing wage for reconstruction is just dumb. The area desperately needs a cash infusion to rebuild, and paying subpar wages will slow the reconstruction. It's bad policy and bad politics.
And Mike the Mad Biologist makes a fair point about the persistence of straightforward racism. I just don't think that's what was at play in No Man's Land.