A Massachusetts State Police trooper was seriously injured in a crash on the Billerica-Chelmsford line on Thursday afternoon.
The accident was reported shortly after 2 p.m. on Route 3 south in Billerica, just south of Route 129, according to state police.
They said the trooper, a 56-year-old man and 33-year veteran of the state police, was conscious and alert and was taken to Lahey Hospital. He is listed in stable condition with serious injuries.
The trooper, assigned to the Concord Barracks, had stopped a car and was out of his cruiser. Police say a 53-year-old Haverhill man driving a Toyota Prius hit the trooper. The driver stopped and remained at the scene.
The investigation is ongoing. State police collision reconstruction and crime scene units responded to the scene.
Traffic in the area was backed up for a time due to the crash, but the scene has since cleared.
No further updates are expected on Thursday night, state police said.