Ontario’s police watchdog is investigating a crash involving a stolen pickup truck in Clarington Sunday afternoon that left one person dead and another seriously injured.

The Special Investigations Unit (SIU) said the incident began in Port Hope, where local police were called about an aggressive driver.

Officers arrived at the scene and discovered two vehicles had collided. The SIU said one of the drivers involved fled and proceeded to carjack a pickup truck.

The suspect, the SIU said, forced the driver of the vehicle, a 28-year-old man, to drive him away from the area.

At some point later, officers with the Ontario Provincial Police spotted the pickup truck and pursued it.

“With the assistance of Durham Regional Police Service officers, a spike belt was deployed. The driver of the pickup truck hit the spike belt and entered the ditch near the Highway 115 southbound ramp to Highway 401,” the SIU said in a release issued Sunday evening.

The suspect was arrested before being transported to the hospital, where he died of his injuries.

The SIU said the 28-year-old driver was also taken to the hospital. There is no update on his condition.

The agency added that a female passenger in the pickup truck was not physically injured.

Two SIU investigators have been assigned to the case, and the agency is asking anyone with information to contact the lead investigator at 1-800-787-8529.

The SIU is called in to investigate whenever police are involved in a death, serious injury, sexual assault allegations or the discharge of a firearm at a person.