Somewhat related: there was a fire in 1973 that destroyed the military records of a large fraction of former military personnel at the time: https://en.wikipedia.org/wiki/National_Personnel_Records_Cen....
However, these particular files (benefits claims files, or C-Files) are a different type of file and never burned. Better yet, they often have some parts of the veteran’s OMPF that were copied *into* the C-File, to establish eligibility for those benefits — copies that were made before the fire! In other words, these files could serve as partial backups…