A truck driver faces multiple charges in connection with a fiery 12-vehicle Highway 400 crash that killed four people in June, including a little girl and two women from the same family.

​Ontario Provincial Police said Thursday that Sarbjit Singh Matharu, 35, of Winnipeg, has been charged with four counts of criminal negligence causing death and one count of criminal negligence causing bodily harm.

The June 24 pileup left four people dead and involved 12 vehicles, including three transport trucks. A truck driver from Winnipeg now faces five charges, including four counts of criminal negligence causing death. (Barry Smith/CBC)

The June 24 crash on southbound Highway 400 near Finch Avenue killed three members of the Vokshi family who were on their way home after a day at Canada's Wonderland.

Five-year-old Isabela Kuci, her mother 35-year-old Valbona Vokshi, and her grandmother, 55-year-old Xhemile Vokshi, were pronounced dead at the scene.

Blerta Vokshi, aunt, sister and daughter to the victims, was in another vehicle involved in the crash with two-year-old Aron Sufa. Both of them survived.

A fourth woman, 27-year-old Maria Lipska, with no relation to the other victims, was also killed in the crash.

More charges possible

Police on Thursday would not provide further details about how the collision transpired, but clarified that 11 vehicles were involved, including three commercial transport trucks.

The crash fuelled a fire that destroyed one of the truck's trailers and two other vehicles.

OPP Sgt. Kerry Schmidt told CBC News the charges were months in the making due to the complexity of the investigation.

"There's been a lot of work, there was so many vehicles involved, so many witnesses to follow up on," he said.

He added that the investigation into the crash isn't complete, and more charges are possible.

Matharu flew in from Winnipeg to make his first court appearance on Thursday at Old City Hall. His bail was set at $15,000. He is also not allowed to contact the victims' families, he cannot travel outside Ontario or Manitoba and he is not allowed to drive.

'Nothing short of a nightmare'

Valbona Vokshi's sister, Blerta, who was injured in the pile-up while riding in a different car, said she didn't have words to express how she felt about the charges.

"This is a nightmare, this whole situation," she told CBC News.

Sandra Zisckind, a personal injury lawyer representing the Vokshi family, said Thursday the family is pleased by the severity of the charges.

"It's a whole bunch of emotions," Zisckind told CBC News when asked how the family is feeling.

"They are trying to cope the best way they know how," she said. "The situation is nothing short of a nightmare."

Investigators have not revealed to her or the family how they think the accident occurred, Zisckind said, and she knows little about the driver or the company that employed him.

"At the end of the day, the most important thing is that justice is done not only for this family, but for the community at large," she said.