The Great East Japan Earthquake of 2011 caused unprecedented damage. Even areas 300 kilometers away from the epicenter suffered damages beyond what was predicted. A phenomenon called soil liquefaction occurred over a large area. Some 27,000 structures sank or tilted, causing massive damage. The city of Urayasu in Chiba Prefecture was particularly affected. Surveys later revealed that the city had all the criteria for liquefaction to occur. The key was groundwater depth. Find out the mechanism of liquefaction and the latest mitigation technology.