U.S. Army Staff Sgt. Michael O’Callaghan, Mike O’Callaghan’s grandson, gives his remarks during a ceremony celebrating the Mike O’Callaghan Military Medical Center’s 25th Anniversary at Nellis Air Force Base, Nevada, Nov. 12, 2019. O’Callaghan told multiple personal stories about moments he and his grandfather had shared together during his speech. (U.S. Air Force photo by Senior Airman Kevin Tanenbaum)