BOISE -- Fire investigators have now determined the cause of a fire on Sun Valley's Bald Mountain.
Investigators say a snowmaking compressor oil cooler malfunctioned.
That caused a lot of compressor oil to leak, which only intensified the fire, as did the wind that night.
Flames destroyed the top lift terminal of the Flying Squirrel Ski Lift and a communications building.
Some ski runs were closed for a while and a ski race canceled.