On May 11, 2006, about 1810 central daylight time (cdt), a Piper PA-30, N8585Y, piloted by an airline transport pilot, sustained substantial damage when it ran off of a grass runway at the private airstrip near Dongola, Illinois. The 14 CFR Part 91 business flight was operating in visual meteorological conditions without a flight plan. There were no injuries. The flight originated from the Eagle Creek Airpark, Indianapolis, Indiana, about 1615 cdt. The pilot reported that upon arrival at his destination, the winds were strong and out of the north. He stated that he decided to land into the wind even though the runway sloped downhill in this direction. He stated that he performed a slow approach in landing configuration and then went around to execute the landing. He stated that the touchdown was normal and that there was intermittent braking for 1,500 feet. He stated that the braking action was "almost impossible" due to the wet grass runway. He stated that he veered the airplane to the left and off of the runway in order to avoid tree stumps at the departure end. The pilot listed the runway direction, length and width as 35, 2,000 feet, and 75 feet respectively. The pilot listed no mechanical problems with the airplane. The airplane contacted a ditch along the side of the runway.