A reactor at the Fukushima Daiichi Nuclear Power Plant explodes and releases radioactivity into the atmosphere a day after the 2011 Tōhoku earthquake and tsunami.

The Fukushima Daiichi Nuclear Power Plant is a disabled nuclear power plant located on a 350-hectare (860-acre) site in the towns of Ōkuma and Futaba in Fukushima Prefecture, Japan. The plant suffered major damage from the magnitude 9.1 earthquake and tsunami that hit Japan on March 11, 2011. The chain of events caused radiation leaks and permanently damaged several of its reactors, making them impossible to restart. The working reactors were not restarted after the events.

On 11 March 2011, at 14:46:24 JST, a M_w 9.0–9.1 undersea megathrust earthquake occurred in the Pacific Ocean, 72 km (45 mi) east of the Oshika Peninsula of the Tōhoku region. It lasted approximately six minutes and caused a tsunami. It is sometimes known in Japan as the "Great East Japan Earthquake" , among other names. The disaster is often referred to by its numerical date, 3.11.

March 12 is the 71st day of the year in the Gregorian calendar; 294 days remain until the end of the year.