On May 14, 1999, at 0945 hours mountain standard time, a Citabria 7GCAA, N9661S, veered off runway 17, ran into a ditch, and bent the left wing while landing at the Buckeye, Arizona, airport. The airplane, operated by Turf Soaring School under 14 CFR Part 91, sustained substantial damage. The airline transport pilot and one passenger, the sole occupants, were not injured. Visual meteorological conditions existed for the personal flight that had departed the Pleasant Valley Airport, Peoria, Arizona, at 0915. The flight was scheduled to terminate at the Buckeye airport. No flight plan was filed. The pilot stated that a run-up was conducted at the Pleasant Valley Airport and no discrepancies were noted with the brakes. He said that the touchdown at Buckeye was normal and on the landing rollout he applied brakes, but the left brake did not activate. He stated that the airplane veered to the right off of the runway. The pilot reported that he took his right foot off the right brake to keep the airplane going in a forward direction. He stated that there was an obstruction in the airplane's path (a hill) and he applied right brake to go around the obstruction but the left main wheel of the airplane had entered a ditch and bent the left wing. The pilot stated that weather was not an issue, and that conditions were clear and the wind was calm. According to a Federal Aviation Administration inspector who examined the airplane, the brake system was intact, with no evidence of a fluid leak. He further reported that he was able actuate the left brake. The inspector stated that during his inspection he was unable to find any discrepancies in the brake system that could cause a failure.