Eugene Clay was born on February 20, 1939, in Snyder, Texas. He enlisted in the U.S. Air Force on February 21, 1956, and was trained as an aircraft mechanic. Airman Clay's first assignment was to the 35th Air Base Group and then the 6102nd Air Base Wing at Yokota AB, Japan, where he served from October 1956 to September 1958. He then transferred to the 340th Air Base Group at Whiteman AFB, Missouri, and served there from September 1958 to January 1961, followed by service with the 3922nd Material Squadron at Nouasseur AB, Morocco, from January 1961 to January 1963. Sgt Clay served with the 494th Organizaitonal Maintenance Squadron at Sheppard AFB, Texas, from January 1963 to January 1965, and then became a helicopter mechanic with the 28th Organizational Maintenance Squadron at Ellsworth AFB, South Dakota, from June 1965 to October 1967. Sgt Clay deployed to Southeast Asia in October 1967 and was assigned to the 37th Aerospace Rescue and Recovery Squadron at Da Nang AB in the Republic of Vietnam. He was killed on November 9, 1967, when the HH-3E Jolly Green Giant helicopter he was a Flight Engineer on was shot down over Laos. His remains have never been recovered.

His Air Force Cross Citation reads:

Staff Sergeant Eugene L. Clay distinguished himself by extraordinary heroism in connection with military operations against an opposing armed force as an HH-3E Flight Engineer in Southeast Asia on 9 November 1967. On that date, Sergeant Clay attempted the night extraction of a ground reconnaissance team after his helicopter had been severely damaged. Two other helicopters had been shot down and a third extensively damaged in previous attempts. During the rescue attempt, Sergeant Clay unhesitatingly exposed himself to hostile fire to assist the survivors to the aircraft. The hostile forces closed in quickly, and as the damaged helicopter departed, it was shot down. Through his extraordinary heroism, superb airmanship, and aggressiveness, Sergeant Clay reflected the highest credit upon himself and the United States Air Force.