Dear Ms. Szczechura,
Thank you for posting your request on History Hub!
Official Military Personnel Files (OMPFs) for those who left the U.S. Army after 1956 and prior to October 16, 1992 are in the custody of NARA's National Personnel Records Center in St. Louis. In many cases where personnel records were destroyed in the 1973 fire, proof of service can be provided from other records such as morning reports, payrolls, and military orders, and a certificate of military service will be issued. If you are the next-of-kin (un-remarried widow or widower, son, daughter, father, mother, brother or sister), please complete a GSA Standard Form 180 and mail it to NARA's National Personnel Records Center, (Military Personnel Records), 1 Archives Drive, St. Louis, MO 63138-1002.
We hope this information helps. Best of luck with your family research!