3 days. Everyone harps on the 3 days. The reason that there is a "local" government is because the "federal" government is far away. Local governments are there to help with the immediate care. Their failure only highlighted the fact that the government in general can't take care of everyone's needs. If your local government fails, the Federal one is too far away to help right away.
Add to that they had to help Mississipi, Alabama and Florida as well as LA, then you can see why its pointless to place blame on the Feds. Its too great a task to tackle all of it within 24 hrs of a disaster. Yet you didnt hear complaining from MI, AL, FL, TX and the rest who got hit by hurricanes about the Federal aid. I wonder why you heard it about LA? Probably because LA had an incompetant mayor backed by an incompetent Governor that didnt know how to run a hotdog stand let alone oversee a rescue and recovery effort for an entire state.
FEMA did exactly what it was supposed to do. The problem is that the politics of the situation seaped through as they too foten do in today's media. No context is given for how long a recovery effort should respond by. No context is given that the surrounding states that received just as much if not more damage then LA were not in disarray thanks to good leaders that prepared for the worst. Too often we hear only half the story.