This wind-powered generator in Higashidori, Aomori Prefecture, came crashing down Monday night, causing power outages to households in the area.(The Asahi Shimbun)

 HIGASHIDORI, Aomori Prefecture–The industry ministry Wednesday said it is trying to determine what caused a 68-meter-high wind turbine to collapse earlier this week since strong winds apparently were not blowing at the time.

The incident at the Iwaya Wind Farm in the Iwaya district of Higashidori in this northern prefecture is thought to have occurred late Monday, according to officials of Eurus Energy Holdings Corp., which manages the wind farm.

While no one was injured, the incident resulted in temporary power outages to homes in the area because power lines were severed.

Company officials, after being alerted by Tohoku Electric Power Co. early Tuesday about a blackout, discovered the wind turbine lying on the ground.

The company is investigating whether the turbine collapsed because of weather conditions, bad design, faulty construction or other reasons.

According to officials of the Nuclear and Industrial Safety Agency at the Ministry of Economy, Trade and Industry, a similar incident in Okinawa Prefecture was found to have been caused by strong winds triggered by a typhoon.

The turbine, one of 25 at the wind farm, measures 3.6 meters in diameter at its thickest point and was set in a concrete base. The blades on the central pillar measure 29 m each. It is designed to withstand winds of up to 216 kph.

Local meteorological officials recorded maximum wind gusts of 27.7 kph on Monday night in nearby Mutsu.

The wind farm began operations in November 2001.

Even though no abnormalities were found among the remaining 24 generators, the company suspended their operation.