York Regional Police are seeking witnesses to a serious all-terrain vehicle collision in the City of Markham.
Investigators say the A-T-V rolled over at about 1:30 a-m Sunday in the area Major Mackenzie Drive.
The driver -- a 25 year-old man from Owen Sound -- was taken to hospital with life-threatening injuries.
Police would like to hear from anyone who witnessed the incident or anyone who may have dash-cam footage
