Selfridge firefighters work with emergency medical technicians from the MedStar ambulance service to treat people with simulated casualties during a Major Accident Response Exercise at Selfridge Air National Guard Base, Mich., June 21, 2011. Military planners at the base often invite local agencies, such as MedStar, to participate in base exercises to enhance the readiness of all personnel to respond to a major incident. (USAF photo by Rachel Barton, 127th Wing Public Affairs)