A long-time Umaine history professor lost his left leg in a bizarre bicycle accident in Passadumkeag.Professor Nathan Godfried, who’s been at the university for 18 years, was riding on Route 2 Sunday afternoon. A colleague says a blade from a riding lawn mower being towed on a trailer fell off and hit Godfried’s leg. A nurse who was passing by stopped and helped Godfried until emergency crews arrived.His left leg had to be amputated at the hospital. Godfried’s teenage son was riding with him.He was not hurt. Authorities say it was a freak accident and no charges will be filed.