[3] Tei Seki was killed in action 31 January 1944 when converted submarine tender Yasukuni Maru[1] was torpedoed.
On 24 January 1944, Yasukuni Maru was assigned to a troop convoy departing Tateyama, Chiba for Truk.
On 31 January, approximately 17 miles (27 km) northwest of Truk, the convoy was attacked by the US submarine Trigger and Yasukuni Maru was hit by two torpedoes.
The Japanese Dōmei news agency reported on 22 September 1944 that he had "died in action" but gave no details.
The dispatch, recorded by a Federal Communications Commission monitor, said that the Yokosuka naval station, near Tokyo, had listed him as a fatality.