Video: 'Japanese earthquake 1923'

(Saturday, September 1, 1923, 11:58:44 a.m. Japan Standard Time) — A devastating earthquake with an approximate magnitude of 7.9 struck the Kanto Plain on the main Japanese island of Honshu today, killing 120,000 people and leaving 2 million homeless as half the city of Tokyo was destroyed.

Varied accounts indicate the duration of the earthquake was between four and ten minutes. Extensive firestorms and even a fire whirl added to the death toll.

Video: 'This 1923 Weather Phenomenon Killed Thousands in Minutes'

The earthquake had a magnitude of 7.9 on the moment magnitude scale (Mw), with its focus deep beneath Izu Oshima Island in Sagami Bay.

The cause was a rupture of part of the convergent boundary where the Philippine Sea Plate is subducting beneath the Okhotsk Plate along the line of the Sagami Trough.

Video: 'Disasters of the Century | Season 3 | Episode 24 | Kwanto Earthquake | Ian Michael Coulson'

In the immediate aftermath of the earthquake, the Kanto Massacre began. Rumors emerged that ethnic Koreans in Japan had poisoned wells or were planning to attack cities.

In response, the Japanese police and bands of armed vigilantes killed ethnic Korean civilians and anyone they suspected of being Korean.

Video: 'Japan's forgotten Crime - Kanto Earthquake Massacre of Koreans 1923 (Documentary, English Subtitles)'

Estimates of the death toll vary, with most third-party sources citing around 6,000 to 10,000.