In November 1944, the U.S. Navy fleet lay at anchor deep in the Pacific Ocean, when the oiler USS Mississinewa exploded. Japan's secret weapon, the Kaiten, a manned suicide submarine, had succeeded in its first mission. The Kaiten was so secret that even Japanese naval commanders didn't know of its existence. And the Americans kept it secret as well. Embarrassed by the attack, the U.S. Navy refused to salvage the sunken Mighty Miss. Not until 2001, when a diving team located the wreck, would survivors learn what really happened.