The Japanese Navy included five Type A midget submarines in the Pearl Harbor raid of 7 December 1941. Transported on board large I type submarines, the midgets were launched near the entrance to Pearl Harbor the night before the attack was to begin. One, spotted trying to enter the harbor before dawn, was attacked and sunk by USS Ward (DD-139) in the first combat action of the as yet unopened Pacific War.
At least one of the midgets was able to enter the harbor and was sunk there by USS Monaghan (DD-354). Another, the Ha-19, unsuccessful in its attempts to penetrate Pearl Harbor, drifted around to the east coast of Oahu and was captured there the day after the attack.Photos: Japanese Midget Submarines
Four of the five Pearl Harbor midget submarines have been found. That sunk by Ward was located by the Hawai'i Undersea Research Laboratory in late August 2002 in deep water, some five miles off the entrance to Pearl Harbor. It remains where it sank as an element of the Pearl Harbor National Historic Landmark. The other three have been salvaged. Ha-19 was recovered immediately after the attack and the one sunk by USS Monaghan a few days later. The third was found off the harbor entrance in 1960. The submarine sunk by USS Monaghan's submarine was buried in a landfill shortly after its recovery. Two are on exhibit, Ha-19 at Fredericksburg, Texas, and the one found in 1960 at Eta Jima, Japan.
One of the five Pearl Harbor midgets is still unaccounted for. Recent studies of Pearl Harbor attack photography have led some observers to argue that one of the midgets was in place off "Battleship Row" as the Japanese torpedo planes came in, and may have fired its torpedoes at USS Oklahoma (BB-37) or USS West Virginia (BB-48). This contention is still controversial, but, if it is true, the "missing" Type A midget submarine may lie undiscovered inside Pearl Harbor.