In the comments to this post, commenter JP left a link for an article Mr. Lewis wrote in October of 2005. I think this article needs a little more publicity than to be buried in a comment thread. The link JP left was for Times Select, but you can find the article for free here.
The essay is truly outstanding if you are interested in Katrina and the aftermath. I recommend you print it out, take a few minutes out of your day and read it.
Thanks to JP for leaving the original link.