On April 25, 2006, about 1630 central daylight time, a Robinson R22 Beta helicopter, N7197K, sustained substantial damage when it rolled onto it's right side near Brook, Indiana. The helicopter was operated by a private pilot. The 14 CFR Part 91 flight was operating in visual meteorological conditions without a flight plan. There were no injuries. In a telephone interview, the pilot reported that he had flown the helicopter to Brook, Indiana, in order to perform cleanup following a previous truck spill. He stated that he completed the cleanup and had taken the material and placed them in garbage bags and then placed the garbage bags in the helicopter. He said that he had started the helicopter and had either just lifted off, or was preparing to lift off when he saw one of his waste hauling trucks. He stated that he decided to have the truck transport the cleanup materials and he removed them from the helicopter and gave them to the truck driver. He said that as he was returning to the helicopter, he could hear the "RPM's" increasing. He decided that it would not be safe to approach the helicopter and decided to stay at a safe distance. He said that about 15 seconds later, the helicopter pivoted on it's right landing skid and rolled on it's side. He stated that when he left the helicopter, he had lowered the collective, and applied the friction locks.