The was an energy accident at the Fukushima I Nuclear Power Plant, initiated primarily by the tsunami of the Tohoku earthquake on 11 March 2011. The damage caused by the tsunami produced equipment failures, and without this equipment a loss-of-coolant accident followed with three nuclear meltdowns and releases of radioactive materials beginning on 12 March. It is the largest nuclear disaster since the Chernobyl disaster of 1986 and the second disaster (after Chernobyl) to be given the Level 7 event classification of the International Nuclear Event Scale.