Hurricane Katrina laid bare a lot of problems and issues which America suffers from. Unable to be ignored or covered up, the tragedy broadcasted these problems to the world not surprisingly. However many Americans were forced to recognise or realise these problems.
This article highlights many of these problems- racism, corruption, cronyism, hypocrisy, poverty, and so on. It might be sort of long, being 4 pages but it's well worth the read.

"To truly grasp how events in New Orleans unraveled, America would have to grapple with its ahistorical understanding of race, ambivalence toward class and antagonism toward government. But those rabbit holes proved too deep and too ugly, and in the end it was a journey the country had neither the will, curiosity nor leadership to make."