Airman 1st Class Chauncy Williams, 49th Material Maintenance Squadron, and Staff Sgt. Shawn Cullen, 49th Civil Engineer Squadron, attach door fabric tensioning straps to their ratchets in the setting up of a BEAR Base dome shelter June 3 at Holloman Air Force Base, N.M. The students set up the shelter as a part of the Structural Contingency Course lesson plan. They tore down the shelter earlier and returned it to operational status the same day. (U.S. Air Force photo/Airman Sondra M. Wieseler)