Thunder Bay’s police are investigating a serious collision on the city’s south side, that has left a person with serious injuries.

Emergency services were sent to the Arthur and Marks Streets area around 2:00 p.m. on Thursday after receiving reports of a collision.

When they got on scene a person was transported to hospital with life-threatening injuries.

Arthur Street was briefly closed while police investigated, but the road was re-opened by 10:15 p.m. that evening.

The Traffic and Forensic Identification units are involved in the ongoing investigation.