ELLSWORTH AIR FORCE BASE, S.D.- (Left) Senior Airman Jennifer Peterson and Staff Sgt. Jeremiah Phelps prepare to move Mark 84 bombs inside a hardened structure, April 21. Both Airmen are assigned to the 28th Munitions Squadron as conventional maintenance crew chiefs. The process of moving and storing munitions inside hardened structures is known as “warehousing.” (U.S. Air Force photo/Airman 1st Class Corey Hook)