Dear Mr. Hardy,
Thank you for posting your request on History Hub!
The Defense Casualty Analysis System (DCAS) Public Use File contains records of U.S. military officers and soldiers who died as a result of either a hostile or non-hostile occurrence in the Korean War, Vietnam War, Gulf War, or War on Terrorism from 1950 through 2005. These include the records of persons who were missing in action or prisoners of war in either the Korean War or the Vietnam War. Beginning in 1975, casualties considered as occurring during peacetime were also included. The records also include deaths resulting from accidents or illness.
The information you seek may be contained in his Individual Deceased Personnel File (IDPF). IDPFs dated after 1976 are in the legal custody of the Army. For the exact location of these files, please write to U.S. Army Human Resources Command, Casualty & Memorial Affairs Operations Division, ATTN: AHRC-PDC, 1600 Spearhead Division Avenue, Department 450, Fort Knox, KY 40122-5405.
If he died while in the United States, there may be a death certificate for him in the state where he died. See the CDC page on Where to Write for Vital Records. The Office of the Armed Forces Medical Examiner issues death certificates for overseas casualties.
There also may be a record of him in the Beneficiary Identification and Records Locator Subsystem (BIRLS) - Death File.
We hope this is helpful.