On August 31, 2007, approximately 1350 mountain daylight time, a Schweizer SGS 2-33 glider, N5731S, sustained substantial damage following a loss of control and subsequent impact with trees while on approach to landing at the Morgan County Airport (42U), Morgan, Utah. The certificated commercial pilot received minor injuries, and the student pilot sustained serious injuries. Visual meteorological conditions prevailed for the instructional flight, which was being operated in accordance with 14 CFR Part 91, and a flight plan was not filed. The local flight departed 42U about 1300. In a statement submitted to the NTSB investigator-in-charge, the flight instructor reported that on short final to Runway 21 the aircraft encountered a gust of wind, which lifted the tail and rolled the glider to the right. The flight instructor stated that by the time he was able to level the wings he was right of the runway centerline and headed toward a group of large bushes/trees, which were also off the right side of the runway. The flight instructor further stated that the airplane's right wing subsequently impacted a tree, which resulted in the airplane flipping over and coming to rest inverted; the impact force to the right wing resulted in substantial damage to the glider. The flight instructor estimated that the wind at the time of the accident was from 240 degrees and between 10 to 15 knots.