On October 2, 2001, about 1100 eastern daylight time, a homebuilt Woodstock I glider, N21468, received minor damage when the canopy came off during a ground tow release at Greene County Airport (WAY), Waynesburg, Pennsylvania. The certificated student pilot was seriously injured. Visual meteorological conditions prevailed at the time of the accident, and no flight plan was on file for the local personal flight, which was conducted under 14 CFR Part 91. According to the student pilot, who was also the builder of the glider, the accident tow release was the fifth of six that were planned for the day. The purposes of the tow releases were to check the glider before a long test flight and to accustom the student pilot to the glider's flight characteristics. According to the driver of the tow vehicle, the student pilot/builder had made the earlier successful tow releases and landings from a paved runway, and was making his first tow release from grass. The driver towed the glider to the starting point, the student pilot boarded it, and he and another individual installed the canopy. The student pilot/builder reported that he checked the security of the canopy with a "push-up" on it, then began the glider tow. Glider liftoff occurred about 38 knots. At liftoff, the glider hit a clump of grass, and the canopy departed the airframe. The student pilot/builder raised his left arm to protect his face, and pulled back on the control stick as he avoided the canopy. The glider stalled about 10 feet in the air and hit the ground. The student pilot/builder suffered a compression fracture of the second lumbar vertebrae. The student pilot/builder later stated that he had had trouble latching the canopy prior to previous tows, and felt that although he pushed up on it to check it, the latching mechanism was probably twisted.