Don't know if anyone has answered you yet, but I believe the President declared LA, MS, and AL to be in federal "states of emergency." I do not believe they were referred to as disaster zones until after the event.
thanks for the clarification;
"With forecasters warning of a category five storm, the president made sure the federal response would not be delayed by already declaring emergencies in Mississippi and Florida just hours after a similar declaration for Louisiana. Such declarations make federal aid available to assist with disaster relief, but they are rarely made before a storm even hits."
http://www.sfgate.com/cgi-bin/article.cgi?f=/n/a/2005/08/28/national/w130330D57.DTL