Associated Press, Published April 11 2011
Companies say North Dakota wind turbine accident uniqueBISMARCK — Experts say the rotor and blades of a North Dakota wind turbine fell off because they weren't properly attached to the box on top of the turbine's steel tower.
Company officials say the March 14 accident north of Rugby was a "singular event" and doesn't indicate a broader problem. It has caused the companies to do more extensive inspections of their wind turbines.
The wind farm is run by Iberdrola (EE'-bur-DROH'-lah) Renewables and the equipment was made by Suzlon Wind Energy.
Iberdrola official Scott Winneguth (WIN'-uh-guth) says the rotor and blades were "misaligned" when they were fastened to the wind turbine's main power shaft.
The rotor was attached with bolts. The alignment problem caused the bolts to fail, and the rotor and blades crashed to the ground.
Nobody was hurt.