Tokyo Metropolitan Peace Day

What Is Tokyo Metropolitan Peace Day?

Every March 10th is "Tokyo Metropolitan Peace Day" (東京都平和の日, Tōkyō-to Heiwa no Hi) in Japan. The date commemorates March 10, 1945, when the Great Tokyo Air Raid (東京大空襲, Tōkyō Daikūshū) — often described as the deadliest single air raid of the Second World War — killed an estimated 100,000 people in a single night and burned about 270,000 homes in eastern Tokyo. The Tokyo Metropolitan Government designated March 10th as Peace Day by ordinance in July 1990 to commemorate the victims and to maintain awareness of the raid's devastating impact.

The Great Tokyo Air Raid of March 10, 1945

On the night of March 9-10, 1945, U.S. B-29 Superfortress bombers (325 took off, and 279 are recorded as bombing the city) flew low over eastern Tokyo — dropping approximately 1,700 tons of incendiary bombs (primarily M69 napalm cluster bombs) designed to ignite the densely packed wooden residential districts of working-class shitamachi neighborhoods. Fanned by strong winds, the resulting firestorm created an inferno that overwhelmed both firefighting capacity and civilian evacuation efforts. The Honjo, Fukagawa and Asakusa districts of the shitamachi (today's Sumida, Koto and Taito wards) were largely burned out in a few hours, and many people who fled to the Sumida River and canals lost their lives.

The Scale of Destruction

The March 10, 1945 raid is often called the deadliest single conventional bombing raid in history. About 270,000 homes were destroyed, leaving roughly one million people homeless in a single night. The raid was followed by continued firebombing of Tokyo and dozens of other Japanese cities through the spring and summer of 1945, cumulatively killing far more Japanese civilians than the atomic bombs.

Memory and Commemoration

The Center of the Tokyo Raids and War Damage (東京大空襲・戦災資料センター) preserves testimonies and documents from survivors. On Peace Day, the Tokyo Metropolitan Government holds a commemorative ceremony and exhibitions on the air raids. In Yokoami-chō Park in Sumida Ward, the Tokyo Memorial Hall holds the remains of victims of the raids, and a memorial listing the names of air raid victims was added in 2001.

More to Know

• Low-altitude tactics: General Curtis LeMay's decision to send the B-29s at low altitude (approximately 5,000-9,000 feet) at night — contrary to previous high-altitude daylight precision bombing doctrine — was intended to maximize the destruction of Tokyo's densely packed wooden neighborhoods with incendiary bombs, with devastating consequences for civilians.
• Yokoami-chō Park: The park where Tokyo's air raid victims are memorialized was also the site of the Great Kantō Earthquake's mass casualties in 1923 — making it a site of double commemoration for Tokyo's two greatest 20th-century disasters.