Investigators say the decision to fly near clouds and rain showers played a role in a motorized glider crash that killed two men in Telluride.

The National Transportation Safety Board says 64-year-old pilot Robert “Glider Bob” Saunders and 66-year-old Ronald Ueckert likely encountered a downdraft – or fierce downward wind – on Aug. 24, 2016, that was too powerful for the aircraft’s engine to overcome.

The Denver Post reports a witness described the engine as straining before the glider crashed into trees.

The NTSB says investigators did not find anything wrong with the aircraft.

Saunders owned and operated “Glide Telluride,” which offers year-round glider rides out of Telluride Regional Airport. Saunders had been on the Telluride Town Council for about a decade.