Oklahoma City Bombing: Immediate Response Authority and Other Military Assistance to Civil Authority (MACA) [open pdf - 151KB]
"At 0902 on 19 April 1995, a massive car bomb, containing approximately 4000 pounds of ammonium nitrate and diesel fuel, destroyed the Alfred P. Murrah Federal Building in Oklahoma City, Oklahoma. The blast killed 169 people and injured 467. By 1600 that afternoon, President Clinton had declared a federal emergency in Oklahoma City. Prior to that time, however, commanders at Fort Sill and Tinker Air Force Base (AFB), relying on the Immediate Response Authority, had already provided support to Oklahoma City civil authorities. Fort Sill released two medical evacuation helicopters, explosive ordnance personnel, and two bomb detection dog teams, while Tinker AFB dispatched two ambulances and a sixty-six person rescue team. In addition to that immediate support, the Secretary of the Army, through his Director of Military Support, subsequently coordinated the efforts of over 1000 Department of Defense (DOD) personnel to perform a myriad of support functions at the height of the operation."
UC Berkeley Law Library: http://18.104.22.168/disasters.php?categoryID=4
The Army Lawyer (July 1997)