On March 11, 2011, the Great East Japan Earthquake triggered an extremely severe nuclear accident at the Fukushima Daiichi Nuclear Power Plant, owned and operated by the Tokyo Electric Power Company (TEPCO). This devastating accident was ultimately declared a Level 7 (“Severe Accident”) by the International Nuclear Event Scale (INES).

When the earthquake occurred, Unit 1 of the Fukushima Daiichi plant was in normal operation at the rated electricity output according to its specifications; Units 2 and 3 were in operation within the rated heat parameters of their specifications; and Units 4 to 6 were undergoing periodical inspections. The emergency shut-down feature, or SCRAM, went into operation at Units 1, 2 and 3 immediately after the commencement of the seismic activity.

Although there were no immediate fatalities, a worker later died from radiation exposure (https://www.reuters.com/article/us-japan-fukushima-radiation/japan-acknowledges-first-radiation-death-among-fukushima-workers-idUSKCN1LL0OA)

Image Credit: NY Times