The president of the power company behind Japan's nuclear disaster has stepped down in disgrace after taking responsibility for the crisis.
Fuel rods are believed to have melted at three of the plant's reactors after huge waves knocked out the utility's cooling systems on March 11.
Leaking radiation prompted the evacuation of thousands of residents in the northeast of the country, and the struggle to contain the reactors is expected to continue well into next year.
It was the worst nuclear crisis the world has seen since Chernobyl and prompted questions over the safety of the industry in general.
Mr Shimizu had come under fire for evading the public gaze when the problems at the plant initially surfaced and then later checking into a hospital, although Tepco never disclosed details of his ailments.
The company has been criticised for being unprepared for the tsunami despite some scientific evidence that earthquake-prone Japan could be hit with a wave of that size.
It reported losses for the year ending March 2011 of 1.25 trillion yen ($15 billion) - one of the biggest deficits ever reported by a Japan company