A Yarmouth man suffered life-threatening injuries after he was thrown from his motorcycle in Naples.

The Cumberland County Sheriff’s Office says 53-year-old Michael Levesque was heading south on Harrison Road on a motorcycle and went off the road around 4 p.m. Wednesday.

Police say Levesque was thrown from his motorcycle. He was not wearing a helmet and hit his head on the pavement.

He was taken to Maine Medical Center with serious head injuries.

Levesque was traveling with several other riders who witnessed the crash but were not involved.

The crash is under investigation. Impairment and speed do not appear to be factors.