Air Force Maj. Matthew Conlan walks through the cavernous tunnel system below his office in the Crystal City area of Arlington, Va. Conlan was injured in Afghanistan in 2005 and returned to active duty to work at the Air Force's counter-improvised explosive device office. DoD photo by Fred W. Baker III Air Force Maj. Matthew Conlan walks through the cavernous tunnel system below his office in the Crystal City area of Arlington, Va. Conlan was injured in Afghanistan in 2005 and returned to active duty to work at the Air Force's counter-improvised explosive device office. DoD photo by Fred W. Baker III SHARE: Download: Full Size (1.53 MB) Credit: VIRIN: 700006-K-OCI54-961.jpg Photo Gallery