In the Wake of the Storm: Environment, Disaster, and Race After KatrinaThe Russell Sage Foundation has issued a report (link to PDF via World Watch link above) about the racial and economics components both before and after Katrina.
From their executive summary:
Minority and low-income Americans are also more likely to be underserved by government and private relief agencies before, during, and after environmental calamities such as Katrina. Before a disaster, minorities are more likely to be underprepared and underinsured, and to be living in unsafe, substandard housing. During a disaster, minorities and the poor are often - due to economics and language barriers - less exposed to disaster warnings, and more likely to encounter ethnic insensitivity from relief workers and government officials. After a disaster, minorities and low-income individuals suffer slow recoveries not only because they have less insurance and lower incomes, but also because they receive less information, fewer loans, and less government relief, and encounter bias in the search for long-term housing.
....
The differential effects of this disaster were neither natural nor an accident. They were consistent with a pervasive continuum in which low-income and minority communities suffer from both higher socioeconomic stress and greater environmental exposures to air toxins, hazardous wastes, and other environmental disamenities.
In many ways this is not surprising, but it is something that should lead to corrective action. As climate instability grows the poor, minorities and elderly will continue to get the worst of it. If a society cannot help those most in need in times of disaster it is failing as a society in my view.