Three people were injured by a tractor at a Darlington parade Sunday, the police department said. A 69-year-old man with the most serious injuries was taken to a Madison hospital by helicopter. Two others -- a 39-year-old man and a 64-year-old man -- were taken to a Lafayette County hospital with minor or moderate injuries, said Darlington Police Department Chief Jason King. The incident occurred at the Canoe Festival parade's staging area, police said. Two were run over by the tractor after it was started by another man who didn't realize it was in gear, causing it to go forward, King said.