SP6 Leon Grover Nelson was killed on 1 July 1967. SP6 Nelson was assigned to 3rd Ordnance Battalion (Ammunition), Explosive Ordnance Disposal Section. SP6 Nelson was one of the Explosive Ordnance Disposal specialists who were cleaning up the Ammunition Storage Point at Duc Pho, Republic of Vietnam, after it had several major explosions. It is believed that SP6 Nelson placed a M406 40mm high explosive grenade next to a 105mm high explosive plastic (HEP) projectile. The 40mm grenade detonated and caused a low order detonation of the 105mm projectile. The combined explosions killed SP6 Nelson instantly.