On February 23, 1997, at 1615 hours Pacific standard time, a Cessna 172M, N20508, was substantially damaged when it swerved and the left wing contacted the runway during a crosswind landing at Petaluma Municipal Airport, Petaluma, California. The private pilot was not injured. Visual meteorological conditions were reported by the pilot for the personal flight. In his report to the operator of the aircraft, the pilot stated that he noted a crosswind of approximately 15 knots while on downwind leg for landing. On final approach a 15-degree crab angle was required, but the wind was smooth and steady. He transitioned to a slip to maintain runway alignment during the landing flare. During landing roll the plane suddenly veered and skidded to the right and full left brake and rudder wouldn't keep the aircraft on the runway. The aircraft veered off the runway to the right and the nose wheel became mired in mud which caused the aircraft to veer further to the right and the left wing tip contacted the ground. In his report, the pilot reported that there were no mechanical malfunctions with the aircraft.