On July 16, 2000, at 0930 central daylight time, a Weatherly 201B, N1261W, piloted by a commercial pilot, was substantially damaged during an overrun on the takeoff roll at the Rothrock Airport, Streator, Illinois. The flight was operating under the provision of 14 CFR Part 137, and was not operating on a flight plan. Visual meteorological conditions prevailed at the time of the accident. The pilot reported no injuries. The local, aerial application flight was originating at the time of the accident. The accident occurred as the pilot was attempting a takeoff on runway 09 (2,400 feet by 60 feet, paved). The pilot reported, "On T.O. the wind switched and I was not aware of it and did not recognize I had a problem until it was too late. Terrain was hard surface runway slightly up slope." The pilot reported the winds had shifted from the east to west to south. The airplane traveled approximately 300 feet off the departure end of the runway and came to rest in a cornfield. The 0945 cdt weather observation at the Bloomington-Normal Airport, 45 miles south of the accident site, indicated the winds were from 270 degrees at 9 knots.