On January 10th, 1943, the Argonaut was attacking a Japanese convoy when she was counterattacked by the convoy escorts. An allied plane witnessed her attack. The submarine was apparently damaged by a depth charge. When she came to the surface, she was subsequently sunk by gun fire from the Japanese destroyers escorting the convoy, with a loss of all crew members. Fire Controlman 3rd Class Morgan was officially declared dead January 11, 1944. His name is listed on the Tablets of the Missing at Manila American Cemetery, Manila, Philippines.