A little girl, her mother and her grandmother are among four people killed in a devastating crash on Highway 400 last week.

CTV News Toronto has confirmed that 35-year-old Valbona Vokshi, her five-year-old daughter Isabela, and the girl's 55-year-old grandmother Xhemile Vokshi were killed when their car became involved in a massive collision on Highway 400 near Sheppard Avenue on Friday night.

Police say 11 vehicles, including three transport trucks, were involved in the fiery crash.

Other members of the Vokshi family were involved in the crash but were travelling in a separate vehicle.

“My heart is broken,” Blerta Vokshi, one of the family members injured in the crash, told CTV News Toronto.

Katerina Seitaj, a family friend, told CTV News Toronto that her friend Valbona was "very hard-working," "kind," and "generous."

"She was always there for her friends, her family," Seitaj said.

The fourth victim of the crash has been identified by her former employer as 27-year-old Maria Lipska.

According to Lipska's Facebook page, she recently graduated from Seneca's Travel and Tourism program.

A spokesperson for The Boulevard Club, where Lipska previously worked, told CTV News Toronto that Lipska had "a lovely spirit" and "was friends with everyone at work."

They said grief counsellors will be on hand at the private waterfront social club to help employees who are shaken by her death.

While updating the media on Monday, OPP Sgt. Kerry Shmidt called the crash, “absolutely tragic” and “absolutely preventable.”

“I’ve never seen a collision of this magnitude,” Schmidt said.

While the cause of the crash has not yet been determined, Schmidt said the speed of one of the transport trucks may have been a factor.

“I can tell you right now that the collision is focusing on the actions of some of the commercial vehicles, or one of the commercial vehicles, to see whether the driver didn’t stop or slow down in time as traffic was slowing down,” Schmidt said.

No charges have been laid.

On Tuesday, less than one week after the deadly crash, the province announced that new commercial truck drivers in Ontario will be required to take an entry-level training program before they can take a road test.

The new program, which will be four-to-six weeks in length, comes into effect on July 1, 2017.

Ontario's transportation minister Steven Del Duca told reporters Tuesday that the training will ensure commercial truck drivers know how to operate a transport truck safely and will eliminate unregistered trucking schools.