The airplane sustained substantial damage at about 1608 Pacific daylight time, during a forced landing following a loss of engine power on initial takeoff climb. The private pilot and sole occupant was not injured. Visual conditions prevailed and no flight plan was filed. According to the pilot, as the airplane climbed through 500 feet, the engine “sputtered” and subsequently “quit.” He executed a forced landing to a construction site. The airplane touched down in rough terrain and its landing gear sheared off.