O'Sullivan, Cornelius Dion, son of Curtis Dion O'Sullivan (qv); b. 27 Apr. 1919; adm. May 1935 (A); left July 1935; Univ. of California; Lieut. USN (submarines); m. 12 May 1942 Katharine, d. of John Black of San Francisco; lost on active service in US submarine Triton (Pacific) 15 Mar 1944.
Cornelius Dion “Sully” O’Sullivan was born at San Francisco, California on the 27th of April 1919 the elder son of Colonel Curtis Dion O’Sullivan OW, United States Army, later Adjutant General of the State of California, and Helen (nee Hooper) O’Sullivan of 2717, Hearst Avenue, San Francisco. He was educated at Westminster School where he was up Ashburnham from May to July 1935. He was admitted to US Naval Academy as a Midshipman Second Class on the 17th of June 1938.
He attended the University of California, Berkeley on a Lexington Scholarship in the Class of 1942, where he rowed for the University and was later appointed as Captain of Rowing. He was a member of the Phi Delta Theta Fraternity and was a member of the orchestra.
His class had been due to graduate in February 1942 but instead graduated on the 19th of December 1941, due to the United States declaration of war on Japan on the 7th of December. He was promoted to Midshipman First Class in 1941and to Ensign on the 19th of December 1941. He was posted to the coastal and harbour defence submarine R-20 on the 31st of May 1942.
He was married at the United States Naval Academy Chapel, Annapolis on the 19th of May 1942 to Kathryn (nee Black) of San Francisco.
He was later promoted to Lieutenant, Junior Grade and was posted to the submarine USS Triton as 2nd Navigator.
The USS Triton (SS-201), under the command of Lieutenant Commander George Kenneth Mackenzie Jr. USN, set sail from Brisbane, Australia on the 16th of February 1943 for what was to be her sixth patrol. She was to operate against enemy shipping in the area between Rabaul, the Shortlands Basin.
On the 6th of March the USS Triton attacked a Japanese convoy consisting of five merchant vessels escorted by a destroyer. During the attack she sank the cargo ship Kiriha Maru and damaged one other ship. Two nights later she attacked another enemy convoy and claimed that five of the eight torpedoes she had fired scored hits. She was unable to confirm this due to gunfire from the escorting destroyers which forced her to submerge.
On the 11th of March the USS Triton reported that she was stalking two convoys, each made up of five or more ships. She contacted the submarine USS Trigger (SS-237) which was operating in an adjacent area. She was ordered to remain to the south of the equator and to continue her pursuit. Two days later she received a warning from her base that three enemy destroyers were in the area and that they were either looking for convoys to attack or were hunting American submarines.
On the 15th of March 1943, USS Triton was off the Admiralty Islands to the north of New Guinea when she reported that she had attacked an enemy convoy and that she was under a depth charge attack by three Japanese destroyers. Nothing further was heard from the submarine, but post war Japanese records indicate that they had sunk a submarine that day in an area slightly to the north west of the USS Triton’s last reported position. One of the Japanese crews reported observing an oil slick, debris and items carrying American markings. The entire crew was lost in the attack. USS Trigger had also attacked the convoy and came under depth charge attack which eventually stopped. They reported afterwards that they heard continued depth charging some distance away which lasted about an hour.
The University of California wrote of him: - “Sully began college life at the University of California and has had little trouble standing at the top of the class. Sully climaxed four years of crew by becoming the Academy's No. 1 oarsman and captain. His unruly hair has been a problem, but he manages to divert attention with his contagious smile.”
He is commemorated on the Tablets of the Missing at Manila American Cemetery.