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 when the first earthquake occurred and sustained major damage related to the earthquake and subsequent tsunami. Rolling blackouts of approximately three hours were experienced throughout April and May while TEPCO scrambled to find a temporary power solution. The blackouts affected Tokyo, Kanagawa, Eastern Shizuoka, Yamanashi, Chiba, Ibaraki, Saitama, Tochigi, and Gunma prefectures. Voluntary reduced electricity use by consumers in the Kanto area helped reduce the predicted frequency and duration of the blackouts. By 21 March 2011, the number of households in the north without electricity fell to 242,927. Tōhoku Electric Power was not able to provide the Kanto region with