On January 19, 1999, at 1830 central standard time (cst), a Cessna 172R, N4172P, operated by a commercial pilot sustained substantial damage when following landing and turning on to the taxiway from runway 26R at Spirit of St. Louis Airport, Chesterfield, Missouri, the airplane veered off of the prepared surface into muddy terrain. Visual meteorological conditions prevailed at the time of the accident. The instructional flight was being conducted under 14 CFR Part 91. There was no flight plan on file. The instructor pilot and dual student reported no injuries. The local flight originated at Chesterfield, Missouri, at 1627 cst. In his written statement, the instructor pilot said that after having performed five previous touch-and-go landings, at Spirit of St. Louis Airport, the student pilot was going to perform the next traffic pattern approach and landing to a full stop. The airplane touched down without incident on runway 26R, 400 feet prior to taxiway Echo 3. The instructor pilot said that it was decided that they would proceed past Echo 3 and turn off of the runway at taxiway C. About 200 feet past taxiway Echo 3, the student pilot told the instructor that he could not see where to turn onto taxiway C. The instructor pilot said that he took control of the airplane approximately 200 feet prior to taxiway C, and began applying brake pressure to slow down. As the airplane approached the taxiway, the instructor said that the airplane "gradually deviated to the left of the runway centerline." The instructor said that he applied right rudder pedal and then the right brake. There was no braking response. The instructor said that he "applied full right brake" and found that "the right brake had no response or pressure and could be applied to its full limit with no resistance felt." The airplane's left main gear departed the edge of the runway and rolled into the snow. The airplane pivoted counter-clockwise until the nose gear contacted a 2 foot thick pile of snow. The airplane tipped forward and right onto the nose gear and right main landing gear causing the outboard 15 inches of the right wing's leading edge to strike the ground. The airplane then righted itself onto all three landing gear. A Federal Aviation Administration (FAA) inspector examined the airplane at Spirit of St. Louis Airport. Part of the airplane's nose gear pant was broken off. The outboard right wing leading edge and forward spar were bent upward approximately 30 degrees, and aft, beginning 15 inches inboard of the wing tip. One propeller blade tip showed leading edge nicks. Flight control continuity was confirmed. The airplane's brake system revealed no anomalies. Examination of the engine, engine controls, and other airplane systems also revealed no anomalies.