On September 8, 2003, at 1000 central daylight time, a Piper PA-20, N5595H, piloted by a dual student and flight instructor, was substantially damaged when the aircraft ground looped during landing roll at the Wausau Downtown Airport (AUW), Wausau, Wisconsin. The aircraft was rolling out on the grass area parallel to runway 12 when the accident occurred. The instructional flight was being conducted under 14 CFR Part 91 and was not on a flight plan. Visual meteorological conditions prevailed at the time of the accident. The dual student and flight instructor reported no injuries. The local flight reportedly departed AUW at 0900. The flight instructor's written statement reported that after completing a preflight inspection, they departed to the local practice area. He noted that upon return to the airport, an "uneventful 3-point landing was performed." He reported that during the rollout, the aircraft began to drift toward the left side of the landing area. According to the instructor, the dual student applied right rudder to correct the drift and the aircraft responded. However, the aircraft continued to track to the right and, despite full left rudder being applied, the aircraft did not "straighten out." He stated that when the aircraft reached the edge of the turf landing area it "immediately ground looped to the right." The left wing tip and left horizontal stabilizer contacted the ground and were damaged. A postaccident investigation verified tail wheel control continuity. Tail wheel freeplay was approximately 3-1/2 inches total. No other anomalies with the aircraft were observed.