A Union County squad car was involved in a traffic crash on Interstate 57.

It happened just before 2:00am Monday.

According to a state police report, the car was parked partially in the left lane, with the emergency lights on, while responding to a different crash.

Authorities say that a tractor trailer was passing another vehicle in the left lane and hit the rear of the squad car.

The officer was not in the car at the time. The truck driver was not injured.

Both vehicles were towed from the scene.