Senior Airman Tony Pauline and Airman Marlene Zeledon scan and photograph a chemical spill for a training exercise March 17, 2015, at the Center for National Response in Gallagher, W.Va. This training is part of the annual Black Flag exercise for first responders. Pauline is a bioenvironmental engineering technician with the 779th Aerospace Medical Squadron and Zeledon is an emergency management specialist with the 11th Civil Engineer Squadron, and both are assigned to Joint Base Andrews, Md. (U.S. Air Force photo/Senior Airman Joshua R. M. Dewberry)