Senior Airman Tony Pauline (left) and Airman Marlene Zeledon (right) scan and photograph a chemical spill for a training exercise at the Center for National Response in Gallagher, WV., March 17, 2015. This training is part of the annual Black Flag exercise for first responders. Pauline is a 779th Aerospace Medical Squadron bioenvironmental engineering technician and Zeledon is an 11th Civil Engineer Squadron emergency management journeyman, Joint Base Andrews, Md. (U.S. Air Force photo/Airman 1st Class Joshua R. M. Dewberry)