The driver tried to help the 15-year-old Lowell girl until paramedics arrived, however she died at the scene.
Officials said the crash happened just after 6 p.m. Wednesday while a group was walking along the Pioneer St. bridge near the Highway 58 intersection.
Troopers said a 57-year-old Dexter man was heading north on the roadway when he came across a small group riding bikes, scooters or skateboards on the side of the road.
The man told police he steered towards the center of the road to avoid the group when he collided with the 15-year-old, who officials say was walking in the middle of the roadway.
State police closed off Pioneer St. while they handle the crash investigation. At this time no charges have been filed.
This is a developing story, updates will be posted when they become available.