At 0820 Mountain time, the airplane was substantially damaged when its left main gear collapsed during landing. The private pilot was not injured. Visual conditions prevailed. The pilot reported lowering the landing gear handle and heard the gear cycle down but could not recall if he saw green, gear-down indicator lights. While in the landing flare, he heard someone call “gear, gear, gear” on the radio, but it was too late for him to go around. The left main gear collapsed on touchdown and the airplane exited the side of the runway.
