I've had a serious lack of faith in trunked systems for some time. They always seem to breakdown when you need them most - think 9/11 in New York.
Listening to the operator in Slidell yesterday.....he relayed how none of the other hams in his area had come up in the 12 hours since the storm went through, even on simplex...it was very sad listening...
Check out the emergency response communication system problems in posts #2206, 2106.