On September 9, 2004 at 2250 eastern daylight time, a Piper PA-28-140, N9621W, owned and operated by a private pilot collided with a deer during takeoff roll on runway 17 at East Cooper Airport, Mount Pleasant, South Carolina. The personal flight was operated under the provisions of Title 14 CFR Part 91 with no flight plan filed. Visual meteorological conditions prevailed at the time of the accident. The airplane was substantially damaged and the pilot and passenger were not injured. The local flight originated from East Cooper Airport, Mount Pleasant, South Carolina at 2245, on September 9, 2004. According to the pilot, during the takeoff roll on runway 17 at approximately 60 knots, a deer ran across the path of the airplane. The pilot attempted to slow down when the deer struck the airplane. The pilot reduced the power and exited the active runway onto a taxiway. Examination of the airplane revealed the left wing spar was damaged. The pilot also stated that deer on the airport has been a problem, and efforts by airport management to eliminated the deer threat is in progress.