1923 Great Kantō earthquake 40,000 who went missing and were presumed dead. According to the Japanese construction company Kajima Kobori Research's conclusive report of September 2004, 105,385 deaths were confirmed in the 1923 quake. The damage from this natural disaster was the greatest sustained by prewar Japan. In 1960, the government declared September 1, the anniversary of the quake, as an annual "Disaster Prevention Day". Because the earthquake struck at lunchtime when many people were cooking meals over fire, many people died as a result of the many large fires that broke out. Some fires developed into firestorms that swept across cities. Many people
2011 Tōhoku earthquake and tsunami intensities were smaller than the actual ones in some places, especially in Kanto, Koshinetsu, and Northern Tōhoku regions where the populace warning did not trigger. According to the JMA , reasons for the underestimation include a saturated magnitude scale when using maximum amplitude as input, failure to fully take into account the area of the hypocenter, and the initial amplitude of the earthquake being less than that which would be predicted by an empirical relationship. There were also cases where large differences between estimated intensities by the Earthquake Early Warning system and the actual intensities occurred in the aftershocks and