On September 4, 1999, about 1010 eastern daylight time, a Cessna 172N, N172AN, registered to American Aviation, operating as a 14 CFR Part 91 instructional flight, experienced a loss of directional control at the Lakeland-Linder Regional Airport, Lakeland, Florida, on landing rollout and crashed. Visual meteorological conditions prevailed and no flight plan was filed. The airplane sustained substantial damage. The commercial pilot flight instructor (CFI) and the student pilot reported no injuries. The flight originated from Brooksville, Florida, about 25 minutes before the accident. The student pilot stated he was flying the airplane and he made a normal landing to runway 23. He applied brakes on landing rollout and the airplane started to veer to the right. The CFI got on the flight controls and they both applied left rudder. The airplane did not respond to the rudder input, and continued off the right side of the runway, through the grass, and collided with the ditch. The CFI stated, "after being cleared to land on 23 LAL while on a right hand base leg, student pilot turns final, reduced power, applied full flaps, approached at 65 KIAS, flared, made soft touch down, approaching turn off applied brakes, aircraft began swerving to right-student and instructor applied left rudder-full left rudder-could not stop motion to right-entered grass, aircraft continued skidding to right and rolled into retaining ditch on right side of runway." Examination of the runway by a police officer from the Lakeland Police Department revealed skid marks that started between the runway touchdown zone markings of the runway and curved to the west edge of the runway extending about 200 feet. Approximately the last 1/4 of the right tire marks exhibited skipping tire markings. There were 204 feet of skid marks through the grass from the west edge of the runway to the edge of the ditch. Examination of the runway and aircraft by the FAA confirmed the Lakeland police officer's assessment of the crash site. A functional test of the airplane brake system revealed no deficiencies.