Today in World War II History—Mar. 31, 1944 POSTED: Sunday, March 31, 2019 by Sarah Sundin Adm. Mineichi Koga (public domain via Wikipedia) 75 Years Ago—Mar. 31, 1944: Vice Adm. Mineichi Koga, Commander-in-Chief of Japanese Combined Fleet, is killed in a plane crash on Mindanao in the Philippines.