[planekT]

Nagin's lawyers stopped him from using the school buses and other city buses. They were afraid of legal problems if there was an accident with a fully loaded bus trying to leave the city.

I wouldn't doubt it. Sounds about par for the course.

[Grampa Dave]

Now add union bus drivers and Nagin's lawyers fear of union bus drivers if they were called up and didn't show up, and non union drivers were used.