The USS Bataan was positioned off the coast of Gulfport, Mississippi to support the relief efforts.  The United States Navy moved additional ships and helicopters into the region at the request of FEMA.  The number of National Guardsmen on duty in the Gulf Coast rose to approximately 8,300 [actually 10,428 Army National Guard and 960 Air National Guard were deployed - 11,388 total]. They remained under their respective governor's control, which enables them to provide law-enforcement support in the affected regions, which is prohibited [to the military] by the Posse Comitatus Act . 
On the right of every page of this site, you will see a link that reads "Hurricane Katrina Phone Hotlines." Whether you think you need to call a hotline or not, please click the link and become familiar with the hotlines that are available to you. The list includes a 24 hour crisis line. Do not hesitate to call the 24 hour crisis line if you have been affected by Hurricane Katrina and you feel overwhelmed, depressed, are grieving, or just need someone to talk to about what you are going through. People care about you and will help you.
Katrina ranks as one of the most punishing hurricanes ever to hit the United States. Damage, costing billions of dollars, has made it one of the costliest storms on record. In New Orleans, floodwaters from the breached levee rose to rooftops in the poorest neighborhood, and in many areas residents were rescued from roofs of homes that became uninhabitable. The hurricane’s howling winds stripped 15-foot sections off the roof of the Superdome, where as many as 10,000 evacuees had taken shelter. An exodus of hundreds of thousands left the city, many becoming refugees, finding shelter with nearby relatives or restarting their lives in states as far away as Massachusetts and Utah.