An 18-year-old man is in hospital with life-threatening injuries following a head-on crash in East Gwillimbury this morning.

It happened near Green Lane and Yonge Street at around 5 a.m.

Police say the 56-year-old driver of a Dodge Journey was headed eastbound on Green Lane when it appears a Honda Civic may have spun into the path of the Journey.

The 18-year-old male driver of the Honda Civic, who is a resident of Newmarket, suffered critical injuries following the crash and was rushed to hospital.

The 56-year-old Bradford man was also taken to hospital with serious injuries.

Roads in the area are closed as police investigate.

It is not yet known what led to the crash but heavy snowfall has created slippery road conditions across the Greater Toronto Area this morning.

OPP Sgt. Kerry Schmidt told CP24 that since the snowfall began 24 hours ago, at least 400 crashes have been reported on GTA highways.

Police are asking anyone with information about the crash to call investigators at 1-866-876-5423, ext. 7704 or Crime Stoppers anonymously at 1-800-222-TIPS.