On Sept. 1, millions of people in Japan took part in various emergency drills such as ducking under desks, avoiding falling objects and evacuating buildings. It was all part of Disaster Prevention Day, which takes place annually to mark the anniversary of the 1923 Great Kanto Earthquake, one of the most destructive natural disasters of the 20th century.
The 7.9 magnitude quake started just before noon. Because many people were cooking, fires spread and were whipped up by winds into "fire tornadoes" that swept throughout the cities of Tokyo and Yokohama. Several neighboring prefectures were also badly affected. To make matters worse, a typhoon hit the Kanto region around the same time. Tens of thousands died within minutes of the quake and further casualties resulted from the 12-meter-high tsunami that struck the coast of Sagami Bay in Izu. Altogether, it's estimated that over 140,000 people lost their lives as a result of the disaster.