1. The 9/11 disaster was the result of an act of war on the United States. No matter how chaotic things may have been, from a psychological standpoint this simple fact made people far less likely to act out in a violent manner against their fellow citizens than if it had been a natural disaster. Since 9/11 I've worked on a number of high-level security and evacuation planning efforts for the New York region, and right in the middle of one of these projects we had a chance to see a large-scale evacuation effort at work -- during the blackout of August 2003. In the aftermath of that blackout we did a pretty detailed assessment of the situation and compared it to 9/11 (because the evacuation process was somewhat similar, and because similar mass transit assets were out of service). The results were very interesting, but in retrospect they are not surprising . . . evacuees from Manhattan on 9/11 were downright cooperative and docile as lambs, while the lack of cooperation and level of hostility among the evacuees in the blackout aftermath was very tangible. On 9/11, people were angry -- at the bastards who destroyed the World Trade Center. In August of 2003, these people were also angry -- at the nameless, faceless, incompetent people (the proverbial "they" that you hear about so often in New Orleans these days) who "must be responsible for this huge inconvenience."
2. The 9/11 attacks also occurred in the financial capital of the world, and most of those who were directly affected by it would probably have more of an "upper class" mindset (at the risk of sounding snobby, I know) than your typical victim in New Orleans. If the 9/11 attacks had occurred in Bedford-Stuyvesant or East New York, I wonder if the crowd behavior would have been different.
I was amazed at how well everyone acted during the blackout.
We get a lot of flack from people, but NY'ers do not react like others typically do. I.E., sports teams victories never result in looting etc etc.
My biggest beef is also with the mentality of the low lifes who porbably could have really helped this situation by moving people along rather than just making it worse. I guess if you have a population like this, it makes it harder. no to blame these people, but they are not making it easier.