In the spring and early summer of 1944 a large group of so-called “fit” POWs were returned to Singapore from Thailand upon completion of the Death Railway.
On September 4th 1944 a convoy of several Japanese transport ships set sail from Singapore. There were two ships carrying POWs - the Rakuyo Maru with 1,317 POWs and the Kachidoki Maru with 900 POWs aboard. On the 12th of September the Rakuyo Maru was torpedoed by the American submarine USS Sealion II at around 5:00am and the Kachidoki Maru received hits from the submarine Pampanito at around 11:00pm that evening. The Rakuyo Maru lost 1,159 POWs while more than 400 perished from the Kachidoki Maru. The Japanese rescued some of the POWs from these two ships, and all were transferred to the Kibitsu Maru and taken on to Japan. None were ever taken to Formosa. The American submarines later returned to rescue a number of British and Australian POWs from the Rakuyo Maru who had been drifting at sea for three days.