For an event such as Hurricane Katrina, what capabilities did U.S. military forces bring?

Cooperation, Collaboration, and Planning in Homeland SecurityThe U.S. Northern Command (USNORTHCOM) was established Oct. 1, 2002, to provide command and control of Department of Defense (DOD) homeland defense efforts and to coordinate defense support of civil authorities. When Hurricane Katrina struck in August 2005, the U.S. government went into action to provide food, shelter, and security for the affected areas, with varying degrees of success. Given the magnitude of the disaster, the government relied on private companies to provide many emergency services.For an event such as Hurricane Katrina, what capabilities did U.S. military forces bring? What did they not bring that, in retrospect, they should have reasonably been expected to provide?Should private security companies be hired by the U.S. government to provide assistance in the event of a major natural disaster, as was the case following Hurricane Katrina?