I remember seeing a brief clip last night of the buses that had just began evacuating from Kenner. They were using yellow school buses. That area is Jefferson Parish, but goodness I hope it wasn't a situation where evacuees tossed the driver and took off. Kinda doubt that, because they were likely traveling in convoys. If that happened we should know soon, because a check will reveal a missing driver or fewer arriving buses at the intended shelter than told to expect.
But it is unlikely that a bus was sitting abandoned with keys in it.