The four engine aircraft was on its way from Cam Ranh Bay to Kadena AFB, Okinawa, carrying a crew of eight. While cruising along the Vietnam shore, about 72 km northeast of Nha Trang, the airplane suffered an in-flight explosion and crashed into the sea off Phú Hiệp. All eight crew members were killed. Crew: Lt Cdr Ralph Burton Cobbs, Lt Donald Edwin Siegwarth, Lt Clement Olin Stevenson, Lt Edward Leon Romig, AN M. J. Savoy, YN2 Jack Ishum Dempsey, ADJ2 Curtis David Collette, ADR2 Stanley Jon Freng.
Probable cause (official findings): It was suspected that the airplane had been sabotaged by Vietnamese communist sympathizers who worked at the base.