Bombing of the Toyokawa Naval Arsenal

The Toyokawa Naval Arsenal opened in December 1939 and grew into one of the Japanese Navy's largest ordnance plants, producing machine guns, ammunition and, later, optical equipment. At its height it employed some 56,000 people, including conscripted workers, members of the women's volunteer corps and students mobilised from middle schools and girls' schools across the region.

Until August 1945 the arsenal had suffered only minor attacks by carrier and land-based fighters. On the morning of 7 August, the day after the Hiroshima bombing, B-29s from the Marianas escorted by P-51s attacked from about 10:13 a.m., dropping more than 3,200 500-pound high-explosive bombs in about 26 minutes.

The plant was devastated and the death toll exceeded 2,500. Different counts exist: figures of 2,477 and 2,544 appear in records and on the memorial, and more recent research has put the number at about 2,670. More than half the dead are said to have been in their teens. Evacuation orders came late and many workers were killed in shelters within the compound or while fleeing through its gates.

A memorial was erected in 1946 and services are held each year on 7 August. Part of the site is used by the Ground Self-Defense Force and Nagoya University, and surviving magazines and fuse stores are preserved in the Toyokawa Naval Arsenal Peace Park, opened in 2018.