Lt. Col. Kevin Perera, commander of 425th Brigade Special Troops Battalion, left, and Capt. Doug Droesch, company commander of A Company, 425th Brigade Special Troops Battalion, walk around a tree cut down by an explosive charge during a demolitions exercise. Soldiers assigned to A Company, 425th Brigade Special Troops Battalion, rigged trees with C-4 plastic explosive during a training exercise at Forward Operating Base Sparta on Joint Base Elmendorf-Richardson, Alaska, March 21, 2013. The exercise allowed the soldiers to train with demolitions and taking down trees to block enemy advance on roadways. (U.S. Air Force photo/Justin Connaher)