On May 29, 2004, about 1130 eastern daylight time, a Mooney M20R, N53WM, was substantially damaged while landing at the Warren-Sugarbush Airport, Warren, Vermont. The certificated commercial pilot was not injured. Visual meteorological conditions prevailed and no flight plan had been filed for the flight that departed Bedford, Massachusetts. The personal flight was conducted under 14 CFR Part 91. According to the pilot, he over flew the airport and did not observe a windsock; however, he was informed over the Unicom frequency that runway 4 was in use, and he observed an airplane depart from runway 4. The pilot entered the traffic pattern for runway 4, a 2,575-foot-long, 30-foot-wide, asphalt runway. The pilot stated that the airplane was approximately 10 feet above the runway, when it encountered a strong wind shear and dropped "fast and hard" onto the runway. The pilot aborted the landing and was informed over the Unicom, that the airplane's left main landing gear had separated. The pilot elected to divert to Lebanon, New Hampshire, where he performed a gear up landing, without further incident. Subsequent examination of the airplane revealed damage to the left wing spar and flap. The pilot reported 913 hours of total flight experience, which included 757 hours in the same make and model as the accident airplane. The elevation at the accident site was about 1,470 feet. Winds reported at an airport that was located about 13 miles northeast of the accident site, and at an elevation of 1,165 feet, about the time of the accident, were from 310 degrees, at 14 knots, with 21 knot gusts.