All but one westbound lanes on Highway 401 has reopened near Pearson International Airport following an early-morning tractor trailer rollover.

It happened in the westbound lanes just past Highway 427 at around 1:30 a.m.

Reports from the scene suggest that the truck burst into flames as a result of the rollover.

The lone male occupant of the vehicle managed to escape the blaze and was subsequently taken to hospital with minor injuries.

The Ministry of Transportation says that the truck was carrying some sort of paper product, which may have allowed the fire to quickly spread.

The westbound lanes of the highway were completely closed for more than nine hours, but police were able to open all but two westbound lanes just before 10 a.m.

“It is going to take at least three or four and maybe more hours before we get this tractor trailer back up on its wheels and the highway reopened but in the meantime it is obviously a huge mess here for traffic,” OPP Sgt. Kerry Schmidt told CP24 shortly after 7 a.m. “Even on the eastbound side, it is backed up past Pearson airport with a lot of visuals delays, people looking over to see the flashing lights.”

Schmidt said that police are still investigating what caused the collision, including the possibility that another vehicle may have been “indirectly involved as a fail-to-remain.”

He said that there is damage to the guardrail where the crash occurred and a buildup of ice that resulted from efforts to extinguish the fire.