Tepco releases recordings of Fukushima nuclear crisis
Tokyo Electric Power Company (Tepco), owner of the crippled Fukushima nuclear plant, has released footage of how it managed meltdowns in three reactors.
In the footage, workers can be seen dealing with what they thought was an explosion and urgently trying to understand the scale of the problem.
Tepco has faced criticism over the way it handled the nuclear crisis.
Last year's meltdown, caused by an earthquake and tsunami, was the world's worst nuclear crisis since Chernobyl.
It led to the mass evacuation of some 160,000 people and has rendered parts of the surrounding countryside uninhabitable.
Tepco initially refused to release the films, but has done so after a change in management.
In the video, Tepco officials are heard urgently calling their headquarters.
"This is serious. This is serious," the video shows plant manager Masao Yoshida saying.
It is part of more than 150 hours of video recorded between 11 March, the day the tsunami hit, and 16 March.
However, while Tepco has released some of the audio and pictures of what happened, large portions of the video are without sound.
Tepco says some parts were edited to conceal the identity of some employees. Faces and names of employees are blurred in sections of the tapes.
The prime minister at the time, Naoto Kan, is also seen rushing into Tepco headquarters, but that part of the tape does not have audio.