The device was found by an employee sorting through boxes for Wonder Book and Video 
Frederick, Md. (DG) – An employee working at a warehouse used by Wonder Book and Video discovered a hand grenade Tuesday afternoon while sorting through some boxes.
Frederick City Police and the Frederick County Fire Marshal’s Office responded to the building located at 1550 Tilco Dr. in Frederick at around 12 PM. They determined the device was an inert MK 2 hand grenade.
Investigators learned by sorting through books, pictures, and old letters that were in the same box as the hand grenade, that the owner of device was probably an Airmen in the United States Air Force that was stationed at Lowery Air Force Base located in Denver, Colorado in the late 1950’s.