Highway 400 may have reopened, but the investigation continues after a multi-vehicle pileup that set off a massive fireball and claimed the lives of three people.
The highway was closed between 88 and 89 for more than 24 hours after a crash involving at least four transport trucks and two fuel tankers spilled thousands of litres of fuel on the road.
The impact sent a wave of fuel and flames rushing down the highway, prompting motorists to run for their lives.
One of three people killed is being identified as Benjamin Dunn, a veteran truck driver and father of nine.
Several others were hurt but have since been treated and released from hospital.
Police suggested the blame may lie with the driver of a transport truck they say crashed into slowing traffic.
There was an earlier drunk driving related crash near this scene that could also have accounted for traffic backups.