U.S. Air Force Staff Sgt. Ricky Gennie, 20th Civil Engineer Squadron structures journeyman, directs a metal container onto a roof at Shaw Air Force Base, S.C., Dec. 3, 2013. Gennie, along with several other Airmen and civilian contractors, crane lifted new skylight windows onto the roof of the 20th Fighter Wing headquarters building to replace old windows. (U.S. Air Force photo by Airman 1st Class Jensen Stidham/Released)