A Toronto police officer fatally shot the driver of a suspected stolen vehicle during an early morning incident in Mississauga, Ontario’s Special Investigations Unit (SIU) reported Thursday.

According to the SIU, officers were investigating a reported vehicle theft from Toronto when they tracked the vehicle to a location in Mississauga shortly after midnight. Upon arrival, the vehicle collided with three unmarked police cruisers. During the encounter, one officer fired at least one shot from the road, striking the driver, who died at the scene.

The SIU confirmed that three other occupants of the vehicle were unharmed and have been taken into custody. Two additional firearms were recovered at the scene. The circumstances leading up to the collision and the shooting remain under investigation by the SIU, which operates independently from the police to examine incidents involving police use of force.