So much about federals not being authorized to work in LA
Q: Did the LA governor ask the President to declare an emergency for the State of Louisiana due to Hurricane Katrina? Did she asked for Direct Federal assistance for work and services to save lives and protect property?
A: She did. On August 27

Q: Did the President declared an emergency in the State of Louisiana? Did the President authorize the Department of Homeland Security, Federal Emergency Management Agency (FEMA), to coordinate all disaster relief efforts? Did the President authorize FEMA to identify, mobilize, and provide at its discretion, equipment and resources necessary to alleviate the impacts of the emergency?
A: He did. On August 27

(Katrina hit in the morning of August 29. The levee broke later that morning)

Q: Did FEMA activate The National Response Plan?
A: They did. On Tuesday, August 30.

Q: Did FEMA have a planned scenario for major hurricane hits?
A: They did, at least more than a year ago. See Scenario 10

Update:
Q: Was the federal army prepared to help after Katrina hit? Did they have to get an order from the President to do so? Did the President have to get a formal request from the LA government to issue such an order?
A: Yes, yes, and no.


Q: Is there anyone else who wants to explain federals not helping in the days after Katrina hit by blaming the city and state government for not asking for federal help?