A 15-year-old Connecticut boy was injured when he was ejected from an all-terrain vehicle and thrown into a tree Saturday afternoon in Harpswell, according to the Cumberland County Sheriff’s Office.

The ATV hit the shoulder of the road at the intersection of Cross and Middle roads, causing the accident.

The juvenile, a passenger on the ATV who was not wearing a helmet, was transported to Maine Medical Center in Portland with serious but non-life-threatening injuries, according to the sheriff’s office.