1944 Tonankai Earthquake

The earthquake struck at about 13:35 on 7 December 1944, with its source in the Kumano Sea off Mie Prefecture. Its magnitude is given as 7.9 by the Japan Meteorological Agency. Strong shaking affected Aichi, Mie and Shizuoka prefectures, and a tsunami reaching several metres, up to about nine metres at Owase, struck the Kumano coast.

The Cabinet Office's lessons-learned report puts the death toll at 1,223. Damage was concentrated in munitions plants built on reclaimed or soft ground around Nagoya and Handa. At the Nakajima Aircraft Handa works and the Mitsubishi Heavy Industries Nagoya aircraft works' Dotoku plant, factory buildings collapsed on workers, many of them mobilised students; commonly cited figures are about 130 dead at Handa and about 60 at Dotoku, though counts vary by source.

Because the disaster hit aircraft production at a critical point in the war, materials on the earthquake were classified and press coverage of the damage was strictly controlled, while it was reported abroad from seismograph records. Relief and scientific survey work were hampered as a result.

Thirty-seven days later, on 13 January 1945, the Mikawa earthquake struck the same region and killed about 2,300 people. Together the two earthquakes and the air raids that began in December 1944 severely reduced output in the Tokai aircraft industry.