A construction crane accidentally shorted out power lines in the Tokyo area early yesterday, causing a massive blackout that cut electricity to more than 1 million homes and shut down train and subway lines.
Power was restored before noon, according to Tokyo Power Electric Co (TPEC).
Authorities said at least 120,000 people were affected by the train delays, and the outage shut down 900 elevators in the capital region, including several dozen with people inside. Officials said most if not all the occupants were rescued soon afterward.
There were no reports of injuries, according to officials.
The crane that caused the blackout was perched on a barge traveling on the Kyu Edo River on the eastern edge of Tokyo when it hit power lines spanning the river, shorting them out, TPEC official Kiyohito Yokoi said.
The power outage, which began at 7:38am, cut electricity to about 1.39 million households in Tokyo and the suburbs of Chiba and Kanagawa, up from the previously announced 800,000 households, according to Naoko Haruyama, another TPEC official.
Public broadcaster NHK reported that construction workers aboard the barge did not realize that the 33m crane was raised too high.
"We heard a huge explosion. After the crane hit the power lines the second time, we saw blue sparks," a witness told NHK.
The severed power lines are part of a massive grid serving the 35 million inhabitants of the Tokyo metropolitan region. One-fourth of Japan's population of 127 million lives there.
The last time Tokyo had a similar blackout was in November 1999, when electricity was cut to some 800,000 households after a Japanese military plane hit power lines.
The number of people affected by the transportation delays yesterday was limited by the four-day Bon summer holiday, or "day of the dead," and the number of passengers during the morning rush hour was far fewer than usual.
Trading at the Tokyo Stock Exchange began as usual despite the blackout. Spokeswoman Mariko Saito said that the bourse, located in central Tokyo, had switched to emergency power sources when the blackout occurred.
The power outages also delayed the opening times of both Tokyo Disneyland and DisneySea -- located in Chiba -- by 52 minutes, said Masami Shimomura, spokeswoman for Oriental Land Co, which operates the theme parks.
Nine of Disneyland's 42 attractions and four of DisneySea's 24 had resumed normal operations by mid-morning, Shimomura said.