This is a topic we rarely talk about. Not only do the victims get tired of trying to get assistance but those people whose job it is or who make voluntary efforts to help victims of a disaster get fatigued also. See this article about compassion fatigue in the post-Sandy environment.
Last March, I posted an article from a NZ Red Cross official about her personal experience with burn out after the Christchurch earthquake. That post can be found here.
I invite your comments and any experiences you care to relate.
Additional Thoughts From the Diva: I think that the trend toward increasing use of young, inexperienced people as FEMA Corps staffers and more reliance on volunteers by the Red Cross is going to result in a many more people experiencing not only fatigue but distress from their disaster duties. Are their sponsors/employers prepared to help them deal with it, before and after deployment?
Recovery Diva 
After one of our town’s disasters, a wise woman warned me, “For every disaster, there are two victims: the one who is hurt, and the one who tries to help.” Too few people trying to do too much for too many for too long.
That does sound like sage advice.