New Orleans hurricane

If F.E.M.A. had 500 buses available for use. Why were they not used before the storm hit? Federal Officials had more than 5 days warning. Buses should have been used for a manditory evacuation. Had they moved people before the storm they would not be now pluckin them off of roof tops.
Had they used the buses before the storm they also would not be moving 23,000 from New Orleans to Huston. Who is running F.E.M.A.?
I don't know the answer but I do know that person should resign.