Who was at fault with Hurricane Katrina?

This morning I watched a discussion between Senators Trent Lott and Barbara Boxer on This Week. What was striking was their discussion of the fires in California and Trent Lott briefly mentioning the Katrina disaster in his own state. The focus emphasized that FEMA might finally have gotten its act together with the fires in California. But Florida has had many big hurricanes hit before Katrina, Mississippi faced an even more direct hit than New Orleans from Katrina, and now California, all seemed to go pretty smoothly. Could it be that the problem was with Louisiana's local government and not FEMA?