A tractor trailer skidded of the westbound 402 near Airport Rd. early Friday morning and landed on its side.
It then caught fire and Sarnia Fire Rescue Services rushed to the scene to extinguish the blaze.
The westbound lanes were closed for about an hour with traffic detoured off the highway at Mandaumin Rd.
They later reopened but will have to be closed later to allow for removal of the big rig.
The westbound lanes fully re-opened just after 3pm. OPP say the truck driver sustained minor injuries.