On August 25, 2002, at 1730 eastern daylight time, an Enstrom 280C helicopter, N51689, sustained substantial damage when it hit a transmission wire during cruise flight and impacted the Grand River at a location about 5 miles southwest of Coopersville, Michigan. The pilot and passenger were rescued from the river. The pilot received serious injuries and the passenger was not injured. The 14 CFR Part 91 personal flight had departed from Zeeland, Michigan, at 1700 on a local flight. Visual meteorological conditions prevailed. No flight plan was filed. The passenger reported they had been "flying down Grand River into the sun (west) at approx 5:00 pm. Weather was great, helicopter was running great - came to a sudden stop. Helicopter pitched up slightly then broke through wire and wrapped around rotor 2-3 turns, nosed over towards water & flared just as it hit the water. At impact the windscreen fell inward and we were able to get out the side doors - which were gone...The sun was very bright and neither of us saw the wire." Witnesses reported seeing the helicopter flying approximately 70 feet over the river. The two transmission wires were approximately 70 feet in height.