Call me crazy here, but there were buses available, locally, that were not used. There is an active google search term for "flooded buses in new orleans". Go have a look at the school bus facility snapped from a helicopter by Phil Coale the day after Katrina. I stopped counting at 100 unused buses sitting there flooded. And I didn't know the President mobilized the National Guard for natural disasters. Silly me, I always thought that was a power held by the governor.Technically, Bush was blamed for the exact same thing that Obama has been blamed with regards to Benghazi. Slow ineffectual response even after information available dictated a more active response (sending buses, national guard etc).
Again I am not saying that I think Bush could have technically done anything better, just pointing out that he was skewered for the exact same thing.
So the majority of the buses in the immediate area (meaning closest to the problem) were not used. Those would be local buses. As in New Orleans Regional Transit Authority buses, New Orleans Public School buses, and so on. Public entities under local control of local officials. And the National Guard was not called out earlier, a power held by the state governor.
What else do you have?