On June 13, 2000, at 0600 hours Pacific daylight time, a Piper PA-20, N7451K, was substantially damaged when the aircraft ground looped during takeoff at Gansner Field, Quincy, California. The airline transport certificated pilot and one passenger were not injured. No flight plan was filed and visual meteorological conditions prevailed for the personal flight that was operated by the owner under 14 CFR Part 91. The flight destination is unknown. The pilot reported that, during takeoff roll on runway 24, the left main landing gear collapsed as the airplane accelerated through about 40 miles per hour. The left wingtip then dropped to the ground and the aircraft ground looped to the left. According to the pilot, the landing gear shock absorber end fitting had broken and separated where it attached to the gear strut. The surface wind was reported calm.