Investigators are continuing to look into the cause of a multi-vehicle crash that resulted in the deaths of four people on Highway 400 on Friday night, including one child.

It happened in the southbound lanes of the highway near Sheppard Avenue at around 9:45 p.m.

Ontario Provincial Police say that there were 12 vehicles involved in the accident, including three transport trucks that sustained significant damage.

“There is some incredible, incredible damage,” OPP Sgt. Kerry Schmidt told CP24 on Friday night. “It’s unbelievable really. There are things I don’t think I have ever seen before.”

OPP initially said that five people had died in the accident; however on Saturday Schmidt told CP24 that four people are deceased.

One of the victims was a child, according to Schmidt.

Two other people suffered non-life-threatening injuries, OPP said.

All southbound lanes of the highway were open by 3:30 p.m.

The northbound lanes of the highway were closed overnight but reopened at Black Creek Drive at around 6:30 a.m.