Three workers at Japan’s crippled Fukushima nuclear plant have been injured, one seriously, when steel construction material collapsed on them.
Tokyo Electric Power said the men were building a 13-metre-high tank that was intended to store water used to cool broken reactors.
One of the three was knocked temporarily unconscious, a TEPCO spokesman said on Friday, and remained in a critical condition in hospital, where he had been taken by helicopter.
Another man appeared to have broken his leg, while the third was able to walk unassisted.
TEPCO has been rushing to make hundreds of tanks to store a huge volume of contaminated water until it can be cleaned and released into the sea.
The news comes as Japanese governor on Friday said he supports restarting two nuclear reactors near an active volcano in southern Japan despite public opposition.
The decision was "unavoidable", Kagoshima governor Yuichiro Ito said. His announcement followed the approval by the prefectural assembly earlier in the day of the restart of the Sendai nuclear power station, 1000 kilometres southwest of Tokyo.
The move set the stage for the two reactors to become the first among the nation's 48 units to be reactivated since regulations were updated following Japan's worst nuclear accident at the Fukushima Daiichi nuclear power station.
Fukushima was hit by a tsunami in March 2011 which sparked meltdowns that spread toxins over a large area, forcing tens of thousands of people from their homes.