U.S. Air Force Master Sgt. Erica Nelson (front) and Senior Airman Trevor Donohue (back) clear a stairwell during military operations on urban terrain (MOUT) training at Fort Dix, N.J. on Nov. 19. Nelson and Donohue are security forces specialists from the New Jersey Air National Guard's 177th Fighter Wing. (U.S. Air National Guard photo by Tech. Sgt. Matt Hecht/Released).
Original public domain image from Flickr