A rare power outage caused by an industrial accident plunged much of Tokyo into chaos for about three hours yesterday, disrupting financial trade, trapping people in elevators and paralyzing transport systems.

The outage, caused by a construction crane on a boat hitting power lines, started early yesterday (local time) as offices were opening and commuters were heading for work.

Power supplies were fully restored about three hours later, and most rail services returned to normal in the capital, many of whose residents are away for the Obon summer holiday period.

"It was really terrible," said Naoko Maruyama, a 29-year-old office worker. "I had never experienced anything like it. I had to wait two hours at home until the trains re-started and it was sweltering because I could not use the air-conditioning."

"It's lucky it happened at Obon," she added.

The outage was the biggest to affect the capital in almost 20 years, a spokesman for Tokyo Electric Power Co (TEPCO) Inc said.

Foreign exchange traders at several banks said they were unable to conduct business because of computer problems.

The Tokyo Stock Exchange was trading as usual, but calculations of the Nikkei 225-share average were frozen in early afternoon trade due to a system error related to the power cut, said a spokesman at the index compiler, Nihon Keizai Shimbun.

Individual stock prices and a series of stock indices compiled by the Tokyo Stock Exchange, including the TOPIX index, were not affected.

Stocks nonetheless rose amid slow, holiday-season trade.

A spokesman for TEPCO, which serves an area with a population of more than 30 million, said more than 1.39 million homes were affected.

Jiji news agency said there were 58 cases of stuck elevators with people trapped inside, but there were no injuries.

Traffic lights went off in at least 440 places, Kyodo news service said, while several businesses reported problems with computer systems.

Tokyo subway authorities said about 120,000 passengers were affected by the outages.

Source: China Daily