There is a story being discussed in the blogosphere that I think is worth knowing about: Hurricane Katrina--Our Experiences by Larry Bradshaw and Lorrie Beth Slonsky, EMTs at a convention in New Orleans who were not able to escape before the hurricane hit.
For an abbreviated version with commentary, Making Light has a thoughtful entry. For another with a lot of discussion about the veracity, see samizdata.net.
The point Bradshaw and Slonsky make is that they banded with other tourists and locals to evacuate safely. They once the group got their food and water needs met, they were cooperative. But they were turned back at a bridge and not allowed to leave the city, with shots being fired over their heads. They made an encampment and it was raided by the police, their food and water confiscated. The police were as much a danger to them as the gangs were.
The authors are socialists and so many doubt their story because they believe the authors have an agenda.
But some of the tale is corroborated. Other people who were at the hotel tell their story here, here, here, and here.
Whatever happened, it sounds like a bad scene. I'll try to track whether people come forward to validate the rest of the story.