---
node: great_kanto_earthquake
type: event
slug: great_kanto_earthquake
title: "Great Kanto Earthquake"
lead: "At 11:58 on September 1, 1923, a magnitude-7.9 earthquake originating in Sagami Bay struck the Kanto plain. About 105,000 people were left dead or missing, most of them killed by fire."
published: 2026-07-09
updated: 2026-08-27
change: "Rewrote the opening body section so that it no longer restates the page's own lead."
previous_hash: "8b6c96b5dcfe1f1a867d23fbf9524d3820f3e848b05372e1c6c6983f71b0b578"
requester: internal
reason: "The section repeated the lead, so the first thing under the first heading was text the reader had already read in the search result."
image_file: great_kanto_earthquake.jpg
image_source: "https://commons.wikimedia.org/wiki/File:Kanto-daishinsai.jpg"
image_author: "Unknown"
image_license: "Public domain"
---

## What happened

Tokyo and Yokohama were destroyed mainly by fire rather than by shaking: almost half of Tokyo's built-up area burned, and at a former army clothing depot in Honjo, where tens of thousands had gathered with their belongings on open ground, a firestorm killed some 38,000 people in a single place. Yokohama, closer to the epicentre, lost a larger share of its buildings than Tokyo did, and the tremor cut the telegraph lines out of both cities, so the country learned what had happened from rumour before it learned it from news.

Amid false rumors, mobs — and in some cases authorities — killed thousands of Koreans, as well as Chinese and Japanese who were mistaken for Koreans.

## Background

The earthquake struck at lunchtime, when cooking flames were burning across the cities, and winds at the edge of a typhoon drove the fires.

## Consequences

Martial law was declared, and Goto Shinpei led an ambitious reconstruction that reshaped Tokyo. The disaster became a foundation of modern disaster planning in Japan — September 1 is now Disaster Prevention Day — and an enduring reminder of how disaster can unleash violence against minorities.