SP4 Daniel E. Helton and SSG Roy Phillips were killed on 12 March 1973. SP4 Helton and SSG Phillips were assigned to the 58th Ordnance Detachment (Eplosive Ordnance Disposal). They were setting up a demolition shot on the demolition range at Fort Irwin, California. The demolition shot prematurely exploded killing SP4 Helton and SSG Phillips, and injuring a civilian observer. The unit had been experiencing problems with sniper fire on the range and it is suspected that sniper fire initiated the explosion.