Fukushima Daiichi is a multi-reactor nuclear power site in the Fukushima Prefecture of Japan. A nuclear disaster occurred there after a 9.0 magnitude earthquake and subsequent tsunami on 11 March 2011. The earthquake triggered a scram shut down of the three active reactors, and the ensuing tsunami crippled the site, stopped the backup diesel generators, and caused a station blackout. The subsequent lack of cooling led to explosions and meltdowns, with problems at three of the six reactors and in one of the six spent-fuel pools. Times are given in Japan Standard Time (JST), unless noted, which is UTC plus nine hours. March 2011 Monday, 7 March Tokyo Electric Power Company (TEPCO) submits a report to Japan's nuclear safety agency which predicts the possibility of a tsunami up to 10.2 metres high at the Fukushima Daiichi nuclear plant in the event of an earthquake similar to the magnitude 7.2 earthquake with accompanying tsunami that devastated the area in 1896. TEPCO actually made this prediction in 2008 but delayed in submitting the report because they "did not feel the need to take prompt action on the estimates, which were still tentative calculations in the research stage". Friday, 11 March 14:46: A 9.1 magnitude earthquake strikes off the coast of Honshu Island at a depth of about . The Fukushima I power plant's nuclear reactors 1, 2, and 3 are automatically shut down by the tremor. Nuclear reactors 4, 5, and 6 were undergoing routine maintenance and were not operating (reactor 4 was defueled in November 2010). The tremor also cut the power plant off from the Japanese electricity grid; however, backup diesel generators kicked in to continue cooling. 14:52: Reactor 1's emergency cooling system, which was capable of running without external power, turned on automatically. 15:03: Reactor 1's emergency cooling system was manually shut down to avoid reactor damage (temperature was not critical at this point). 15:27: The first tsunami struck the plant. 15:30: The emergency condenser designed to cool the steam inside the pressure vessel of the No. 1 reactor fails. 15:46 (approximate): A tsunami, unleashed by the earthquake, overtops the seawall designed to protect the plant from a tsunami of , inundating the Fukushima facility and disabling the backup diesel generators – all but one of which were housed underground – and washing away their fuel tanks. With the loss of all electrical power supply, the low-pressure core spray,