Unbelievable stories of indifference and brutality on the part of so-called rescuers and emergency personnel:

Hurricane Katrina — Our Experiences (EMS Network, also cited in Daily Kos)
Photojournalists Covering Katrina Fall Victim to Growing Violence, Chaos (National Press Photographers’ Ass’n)

Plus one story of how well things could go when people organize themselves and there’s a sympathetic authority in place: EMS at Hilton New Orleans Riverside (EMS Network)