On February 18, 1999, at 1430 central standard time, a Bellanca 7GCBC, N57468, piloted by a commercial pilot, sustained substantial damage resulting from an in-flight collision with transmission wires while maneuvering over Prairie Lake, near Grand Rapids, Minnesota. Visual meteorological conditions prevailed at the time of the accident. The flight was operating under the provisions of 14 CFR Part 91 as a business flight. The flight was not operating on a flight plan. The pilot and one passenger reported no injuries. The flight departed Grand Rapids/Itasca County Gordon Newstrom Field, near Grand Rapids, Minnesota, at 1315, for a local flight. According to the pilot's written statement, he was practicing a landing approach to the frozen lake. The pilot stated that on approach to the frozen lake he struck the unmarked transmission wires with his vertical stabilizer. The pilot stated that he retained control of the aircraft and landed on the frozen lake. The pilot did not report that any engine or flight control anomalies were present before the airplane contacted the transmission wires.