One of four people killed in a multi-vehicle crash on Highway 400 on the weekend is believed to be a 4-year-old girl, Ontario Provincial Police say.

The collision happened at around 9:45 p.m on Friday in the southbound lanes of the highway near Sheppard Avenue.

According to OPP, 11 vehicles – including three transport trucks – were involved in the crash and sustained significant damage.

On Saturday, Sgt. Kerry Schmidt confirmed that four people had died as a result of the accident, one of which was a child.

This morning, Schmidt said the child is believed to be a 4-year-old girl.

“After speaking to investigators, I can tell you there is some new information. We’ve been working very closely with the office of the chief coroner and forensic pathology, working on identifying the deceased, working to notify the family,” Schmidt said from the scene via Periscope on Monday morning.

“The investigation still has a long way to go. I can tell you right now that we believe one of the deceased is a 4-year-old girl. There were three (victims) in that vehicle. Another victim in another smaller car. The three victims from that one car were believed to all be family and one of them was a 4-year-old girl.”

The fatal collision triggered a blaze that ultimately caused extensive damage to the highway. Schmidt said that portions of the highway had to be repaved as a result.

“I’ve never seen a collision of this magnitude and the fact that a fire consumed three of the vehicles – a trailer and two more cars – sadly, we’re having a difficult time identifying the deceased because of the fire,” he said.

Schmidt said that three of the victims are believed to be female, but did not confirm the gender or age of the fourth victim.

Though no charges have been laid in the crash, Schmidt said Monday that investigators are looking into whether the “actions of one driver” is to blame for the fatalities.

“The collision (investigation) is focusing on the actions of one of the commercial vehicles, to see whether the driver did not stop or slow down in time as traffic was slowing down,” he said.

Investigators believe that traffic on the highway had been slowing down prior to the crash and a transport truck approached from behind and "started a sequence of events."

"A vehicle driving in the same situation would not be capable of causing this kind of damage," Schmidt told CTV Toronto. "When a vehicle that's loaded with 18 wheels and 80,000 pounds comes into traffic, that's when you see this kind of trauma."

Schmidt added that autopsies will be conducted on the victims sometime today and that investigators have spoken to all the family affected by the collision.

He also urged witnesses to call the OPP.

"You may not think it (the information) is very valuable but it could be the piece we are looking for."