A 52-year-old Cumming man was ejected from his motorcycle and killed after a large amount of oil sprayed from the engine onto the road, the Forsyth County Sheriff’s Office said Tuesday.

Early Saturday, Donald Stone was driving a 2003 Harley-Davidson on the Buford Dam Road bridge over Ga. 400, Forsyth sheriff’s spokesman Peter Sabella said. Investigators, who responded about 1:30 a.m., believe the oil spill caused Stone to lose control of the motorcycle. He struck the guard rail after being thrown from the bike.

The investigation is ongoing.