The 1923 Great Kantou earthquake struck the Kantou plain on the Japanese main island of Honshuu at 11:58:44 a.m. on September 1, 1923. Varied accounts hold that the duration of the earthquake was between 4 and 10 minutes.
The quake had a magnitude of 8.3 on the Richter scale, with its focus deep beneath Izu Ooshima Island in Sagami Bay. It devastated Tokyo, the port city of Yokohama, surrounding prefectures of Chiba, Kanagawa, and Shizuoka, and caused widespread damage throughout the Kantou region. The power and intensity of the earthquake is easy to underestimate, but the 1923 earthquake managed to move the 93-ton Great Buddha statue at Kamakura. The statue slid forward almost two feet.
Casualty estimates range from about 100,000 to 142,000 deaths, the latter figure including approximately 40,000 who went missing and were presumed dead.
The first raid using low-flying B-29s carrying incendiaries to drop on Tokyo was on the night of 24–25 February 1945 when 174 B-29s destroyed around one square mile of the city.
Changing their tactics to expand the coverage and increase the damage, 335 B-29s took off to raid on the night of 9–10 March, with 279 of them dropping around 1,700 tons of bombs. Fourteen B-29s were lost. Approximately 16 square miles of the city were destroyed and some 100,000 people are estimated to have died in the resulting firestorm, more than the immediate deaths of either the Hiroshima or Nagasaki atomic bombs.
The US Strategic Bombing Survey later estimated that nearly 88,000 people died in this one raid, 41,000 were injured, and over a million residents lost their homes. The Tokyo Fire Department estimated a higher toll: 97,000 killed and 125,000 wounded. The Tokyo Metropolitan Police Department established a figure of 124,711 casualties including both killed and wounded and 286,358 buildings and homes destroyed. Richard Rhodes, historian, put deaths at over 100,000, injuries at a million and homeless residents at a million.