From increased truck traffic to an exploding tanker truck to the possibility that a truck collision may have triggered it, trucks played a key role in a fatal pileup of more than 60 vehicles in the fog on Hwy. 401 in Ontario Friday morning.

Seven people, including at least one truck driver were killed the pileup near Windsor. In one spot, jammed with so many burning and mangled vehicles that emergency crews called it the "hot zone," 14 cars and five tractor-trailers were crumpled together in an almost unrecognizable mass. The fire, caused by an exploding tanker truck, was so severe that rescuers were forced back and had to listen to the screams of burning victims.
One trucker, who managed to avoid the accident by hitting the median, told the Toronto Star that, while comforting survivors for an hour after the accident, he ran into a driver who he believes was involved in the collision that set off the chain reaction. George Pare says he talked to a driver who was bobtailing and slowing down in the right-hand lane to turn off the highway. The bobtail driver said he was rear-ended by a tractor-trailer from the U.S. Behind him, another tractor-trailer jackknifed as the driver tried to avoid the first collision.
Pare also described the heavy fog that contributed to the pileup. He had been driving through wispy patches of fog, when a thick wall of heavy fog suddenly loomed. According to published reports, the fog was a mixture of pollution and humidity which developed over Detroit and Windsor before moving over the highway.
In addition to the fog, Windsor Mayor Mike Hurst said the increased truck traffic generated by the North American Free Trade Agreement was also a factor, according to the Toronto Star.