Calvin Obergfell

**DD-687** refers to the USS *Callaghan*, a Fletcher-class destroyer commissioned in 1943. She served with distinction in the Pacific Theater during World War II, providing escort, shore bombardment, and anti-aircraft support during major campaigns such as Leyte Gulf and Okinawa. On July 28, 1945, USS *Callaghan* was sunk by a Japanese kamikaze off Okinawa, making her the last Allied ship sunk by kamikaze attack in the war. **RIVRON 13** (Riverine Squadron 13) was a U.S. Navy unit established during the Vietnam War as part of the Mobile Riverine Force. Activated in 1967, RIVRON 13 operated river patrol boats (PBRs) and other craft in the Mekong Delta, conducting interdiction, troop transport, and fire support missions. The squadron played a crucial role in disrupting Viet Cong supply lines and supporting ground forces until its deactivation as U.S. involvement wound down in the early 1970s.