York Regional Police closed King-Vaughan Road between Keele and Dufferin streets following the accident.
A Honda Accord carrying three teenagers was passed by a BMW early in the morning. The 16-year-old driver of the Accord lost control of the car and went off the road, hitting a tree.
All three occupants of the car suffered injuries, but none of them were life-threatening. One person had to be extricated from the car.
Police are now searching for the driver of the BMW. They continue to investigate.