Wind power group Eurus Energy Japan Corporation is investigating the collapse of one of the Siemens 1.3 MW turbines at its 32.5 MW Iwaya wind farm early last month, says the company's Mitsue Usami. At the time of the collapse, in which the turbine tipped over from its base, winds were 20 m/s and the machine was switched off. The strong wind presented no risk to the turbine, although delayed work by a maintenance crew. The cause of the accident remains unknown, says Usami. Eurus learned of the collapse only after hearing from workers at utility Tohoku Electric Power Company, who had gone to fix power cables dragged down by the machine's fall. Subsequent spot checks at Eurus wind farms across Japan, including those in mid-construction, have not revealed other problems.