Why during Hurricane Katrina, when people evacuated, what followed was looting, murder, rape, etc .. BUT?

When people are evacuating from the California wild fires, when they evacuate there is no looting, murder, rape, and more folks are helping one another that not? What is the big difference?
Update: Are some of you implying that it is more acceptable to murder, loot and rape if you come from a low income? Income should have nothing to do with civility!
34 answers 34