Learn more about the Fukushima disaster from these resources:
Fukushima Wikipedia Page
The magnitude 9.0 Tohoku earthquake on March 11, 2011, which occurred near the northeast coast of Honshu, Japan, resulted from thrust faulting on or near the subduction zone plate boundary between the Pacific and North America plates at a depth of 32 km.  The earthquake resulted in major loss of human life, as well as extensive damage to infrastructure along the entire east coast of Honshu. A tsunami, several fires, and catastrophic nuclear meltdown resulted from the earthquake.
The Tohoku earthquake resulted in a Pacific-wide tsunami with the highest run-up height of 38.9 at Iwate Prefecture. It is considered to be the largest tsunami in Japan since instrumental record began in 1900 and is the fourth largest in the world.
The tsunami and earthquake triggered a destabilization at Fukushima Daiichi Nuclear Power Plant's reactors 1,3, and 4 resulting in hydrogen-air explosions and partial nuclear meltdown.
As a result of the nuclear meltdown
 USGS Significant Earthquake Archive: earthquake.usgs.gov/earthquak...01xgp/#summary