A Massachusetts trooper was injured in an accident on I-93 southbound in Milton.
The incident happened around 1:30 a.m. Wednesday.
State police said a trooper was assisting other troopers who had stopped a wrong-way driver going north on the southbound side.
Then the trooper was walking the driver, who had been arrested on an OUI charge, back to another trooper's cruiser, another driver hit the stationary cruiser, pushing that cruiser into the trooper, which resulted in a lower body injury.
The trooper was taken to Boston Medical Center with non-life threatening injuries.
The motorist who hit the cruiser was taken to Milton Hospital with non-life threatening injuries. It's unclear if this driver will be charged.
The names of the trooper who was injured and the driver who was arrested on an OUI charge have not been released.
After the crash, two travel lanes were blocked. All travel lanes were reopened as of 4 a.m.
The incident is under investigation.
Editor's note: State police had initially said the crash had happened in Quincy, but later clarified it was in Milton.