Colorado investigation shows improperly installed ski lift parts caused accident at Vail Resort

An accident that sent two passengers tumbling from a chairlift at Vail Resort in January was caused by components that were improperly installed when the lift was built nearly two decades ago, according to a state investigation obtained by CBS News Colorado.

The Jan. 25 incident on Vail's Little Eagle Lift, a triple chairlift, threw two passengers from their chair. Neither was injured, according to the Colorado Passenger Tramway Board investigation. About 40 other passengers were evacuated by Ski Patrol using ropes while the lift remained suspended. The lift remained out of service until the state completed its investigation on Feb. 10.

Investigators determined that when the Little Eagle Lift was constructed in 2007, a component of the sheave train assembly was installed upside down. The report concludes the installation error ultimately led to the January malfunction.

State inspectors acknowledged the problem would have been extremely difficult to detect during routine visual inspections. The investigation states that "recognizing that the sheave train was not installed correctly... proved to be extremely difficult... very difficult to visually observe."

Investigators also concluded that when the lift was built in 2007, "clearances should have been reviewed by the design engineer/installer at the time of the installation."

The 19-page report says the affected components were reinstalled correctly, hardware was replaced or inspected as needed, and testing confirmed the lift was operating properly before it returned to service.

CBS News Colorado requested comment from Vail Resorts on the state's findings but did not immediately receive a response.