I don't have an article, but I was listening to NPR last night, and the commentator was saying the evacuation was really bungled due to an organization and communication problem. No one took charge and said, hey I'm running the show, get 2000 buses and send them down, because no one felt they were in charge. FEMA, State & local police, National Guard, all were not sure what the other guys were doing and so waited for overall direction, which never really came.
Why didn't anyone send more buses to the Superdome earlier?