A Butler police officer on his way to a call was hurt Saturday afternoon in a two-vehicle crash at South Main and Cunningham streets, authorities said.

Lt. Chad Rensel was driving an unmarked police car with emergency lights and siren activated about 2 p.m. when the car was struck by a sport utility vehicle at a traffic light, according to investigators.

Rensel, 44, was treated at Butler Memorial Hospital for apparent minor injuries and he was later released.

State police are handling the investigation because a city officer was involved in the crash.

Rensel was traveling east on Cunningham Street in a Ford Interceptor and the other vehicle, a Ford Escape driven by Crystal Raab, 34, of Butler, was northbound on South Main Street when the collision happened, said state police Cpl. Greg Bogan.

The SUV struck the back passenger side of the police vehicle, which was in the left lane and “almost through the intersection,” Bogan said.

At the time, Rensel and a trailing officer in a marked cruiser, which also had its lights and siren activated, were on their way to Elm Street for a terroristic threats call reportedly involving a man with a knife.

Raab was not injured, police said. She was not wearing a seat belt. Rensel had his seat belt on.

A Butler Ambulance Service crew tended to the officer before he was taken to the hospital for further medical treatment, police said. The Butler Fire Department also assisted.

Both vehicles had to be towed.

Bogan said he spoke to “at least three or four witnesses” as part of the ongoing investigation.

He said that police are also trying to determine if a Butler Transit Authority bus, which was eastbound on Cunningham Street near Rensel's car, may have captured the crash on dash-cam video.

Another city officer responded to the terroristic threats call, which ended in an arrest Sunday. No other information about that case was immediately available.