World War II Medal of Honor Recipient. He was issued the award posthumously on March 6, 1946, for his actions as a private first class with Company D, 21st Infantry Regiment, 24th Infantry Division, US Army, on May 14, 1945, at Mintal, Mindanao, Philippine Islands. He joined the US Army in May 1943 and after his basic and combat training, he was sent to the Pacific Theater of Operations While at Mintal, Mindanao, Philippines. he repeatedly distinguished himself by his actions in battle and by volunteering for hazardous assignments, such as evacuating wounded and repairing a bridge under heavy fire and was killed after running through intense hostile fire to reach an abandoned machine gun during a mission to evacuate wounded soldiers. He was also awarded the Purple Heart. His Medal of Honor citation reads: "As a member of the machinegun section, he displayed extreme gallantry and intrepidity above and beyond the call of duty. When a Japanese sniper rose from his foxhole to throw a grenade into their midst, this valiant soldier charged and killed the enemy with a burst from his submachine gun; then, by delivering sustained fire from his personal arm and simultaneously directing the fire of 105mm. and .50 caliber weapons upon the enemy pillboxes immobilizing this and another machinegun section, he enabled them to put their guns into action. When 2 infantry companies established a bridgehead, he voluntarily assisted in evacuating the wounded under heavy fire; and then, securing an abandoned vehicle, transported casualties to the rear through mortar and artillery fire so intense as to render the vehicle inoperative and despite the fact he was suffering from a painful wound. The following day he again volunteered, this time for the hazardous job of repairing a bridge under heavy enemy fire. On 14 May 1945, when leading a patrol to evacuate casualties from his battalion, which was cut off, he ran through a virtual hail of Japanese fire to secure an abandoned machine gun. Though mortally wounded as he reached the gun, he succeeded in drawing sufficient fire upon himself so that the remaining members of the patrol could reach safety. Pfc. Diamond's indomitable spirit, constant disregard of danger, and eagerness to assist his comrades, will ever remain a symbol of selflessness and heroic sacrifice to those for whom he gave his life."