ELLSWORTH AIR FORCE BASE, S.D.- Munitions conventional maintenance crew members store a Mark 84 bomb inside a hardened structure, April 21. The 28th Munitions Squadron is responsible for more than 1,600 munitions line items, 87 facilities, 3.5 million pounds net explosive weight and 640-acres of munitions storage area. (U.S. Air Force photo/Airman 1st Class Corey Hook)