On August 6, 1993, at 1415 hours Pacific daylight time, a Mooney M20J, N1153K, sustained substantial damage during a ground loop following a loss of directional control on takeoff at the King City, California, airport. Visual meteorological conditions prevailed at the time and no flight plan was filed for the operation. The certificated private pilot and his two passengers were not injured. The flight was originating at the time of the mishap as a personal cross country flight to San Jose, California. According to the pilot, the ground loop was induced when the right seat passenger accidentally pressed on the left rudder pedal as the aircraft neared lift off airspeed during the takeoff. The pilot reported that the aircraft yawed 45 degrees to the left when the passenger stepped on the left rudder pedal, and, he could not regain control of the aircraft prior to the ground loop.