Airmen with the 628th Medical Group decontaminate a victim during a mass casualty exercise held on Joint Base Charleston, S.C., June 25, 2010. The exercise simulated the explosion of a ?dirty bomb? at a base softball field which caused 100 simulated casualties. A dirty bomb is a chemical-type weapon that combines radioactive material with conventional explosives. The weapon contaminates the area around the explosion with radioactive material. (U.S. Air Force Photo/Airman 1st Class Lauren Main)

Airmen and Sailors from Joint Base Charleston, S.C., are hosed down for mass decontamination during an exercise which simulated the explosion of a bomb June 25, 2010. The initial mass decontamination washes away any chemicals or toxins which victims have been exposed to in the event of a real chemical attack. (U.S. Air Force Photo/Airman 1st Class Lauren Main)

A member of Joint Team Charleston is hosed down by Jeff Feltner while playing the role of a casualty during a mass casualty exercise on Joint Base Charleston, S.C., June 25, 2010. The exercise simulated 100 casualties that occurred as a result of a simulated explosion near a base softball field. Eighty-six of the casualties were played by Sailors from the Naval Weapons Station. Mr. Feltner is a fire captain with the 628th Civil Engineer Squadron. (U.S. Air Force Photo/Airman 1st Class Lauren Main)

Airmen from the 628th Medical Group transport a casualty to an ambulance to receive further medical attention during a mass casualty exercise on Joint Base Charleston, S.C., June 25, 2010. Responders to the simulated incident included the 628th Civil Engineer Squadron to eliminate fires caused by the explosion and to dispose of any additional explosive material. The 628th Security Forces Squadron set up a cordon, secured the area, and the 628th Medical Group provided emergency medical attention to victims. (U.S. Air Force Photo/Airman 1st Class Lauren Main)

An Airman from Joint Base Charleston plays the role of a pregnant casualty during a mass casualty exercise on Joint Base Charleston, S.C., June 25, 2010. The Airman simulated giving premature birth to a 7-month-old baby following the explosion of a bomb. (U.S. Air Force Photo/Airman 1st Class Lauren Main)

Jeff Feltner hoses down members of Joint Team Charleston during a mass decontamination following a simulated bomb explosion on Joint Base Charleston, S.C., June 25, 2010. Explosive Ordnance Disposal assisted with the simulated explosion by setting off a block of C-4 at the explosives range. Security forces, the fire department and medical personnel responded immediately to gain control of the situation. Mr. Feltner is a fire captain with the 628th Civil Engineer Squadron. (U.S. Air Force Photo/Airman 1st Class Lauren Main)