On Dec. 8, 1941, Ensign Kazuo Sakamaki, the Japanese commander of a mini submarine, and his craft were captured on Bellows Army Airfield following the Japanese attack on Pearl Harbor. A map found within the sub revealed some surprises about the security of the Hawaiian Islands and the U.S. Navy’s Pacific Fleet.

The Japanese attack on Pearl Harbor was meant to be a two-prong aerial and submarine attack. More than thirty submarines were to take part, among them five two-person, 78-foot-long, mini submarines of the Special Attack Unit that were to enter the harbor quietly and fire on American ships berthed around Ford Island after the aerial attack began. One of these subs, I-24tou, was commanded by 24-year-old Lieutenant Sakamaki, who wrote in the ship’s log, “Today I will shoulder one important mission and, diving into Pearl Harbor, will sink the enemy’s warships.”

At 3:30 a.m., on Dec. 7, Sakamaki and Petty Officer Kiyoshi Inagaki launched their mini sub from its mother ship about ten nautical miles southwest of the entrance to Pearl Harbor. Sakamaki immediately noted several problems; most concerning were the sub’s malfunctioning gyrocompass and steering difficulties. Over the next few harrowing hours, Sakamaki and Inagaki veered way off course, hitting the coral reefs around the island of Oahu several times. At 8:17 a.m., the U.S.S. Helm discovered and fired on the sub; smoke and poisonous fumes rendered the crew unconscious. When Sakamaki came to and found the sub lodged on a reef, he ordered Inagaki to abandon ship while he set the self destruct charge and swam to shore.

The next morning, Soldiers of the Hawaii National Guard found a naked Sakamaki and his wrecked sub on Waimanalo Beach on the east coast of Oahu near Bellows Army Air Field. Sakamaki was turned over to the Federal Bureau of Investigation, which called in Army Capt. Gero Iwai, chief of the Translation Section of the local Counter Intelligence Detachment, and fellow Nisei Douglas Wada, a naval counterintelligence officer, to interrogate the captured Japanese officer. Sakamaki refused to cooperate, repeatedly but unsuccessfully requesting the means to kill himself. Three days later, the body of his crewmate, Inagaki, was recovered from the ocean.