A 50-year-old cement truck driver has been charged in connection with a horrific accident that killed five people -- including three children -- in Calgary Friday night.

The victims were crushed after the car they were in, which was stopped at a red light, was rear-ended by a Mack 700 Tri-Axel cement truck.

Police say the northbound Chrysler Intrepid was stopped at a red light located at the intersection of MacLeod Trail and 194 Avenue Southwest around 7 p.m. on Friday when it was struck from behind by a 2005 Mack 700 Tri-Axel cement truck.

"The force of the impact lodged the Intrepid under the front of the cement truck and the momentum of this truck pushed this vehicle nearly 300 metres northward where it finally came to rest in the east curb lane and shoulder," a statement from Calgary police said.

A male driver, 41, and a female passenger, 33, were pronounced dead at the scene.

A six-year-old girl, nine-year-old girl and 16-month-old baby boy were also killed in the crash. Police say all three children were properly restrained in the back seat of the vehicle at the time of the collision.

The cement truck driver, Daniel Tschetter of Cochrane, Alta., was uninjured in the crash. The identities of the deceased have not been released.

Police say the tangled wreckage of the vehicle has created problems for investigators. Only some of the next of kin have been notified.

"The wreckage of the vehicle made it extremely difficult for extrication and so the medical examiner's office has not been able to complete their work in order to confirm (identities) and do the notification of the next of kin," Duty Inspector Guy Slater told CTV.ca on Saturday.

Police have not said if those killed were members of the same family or Calgary residents.

Slater said excessive speed and alcohol are believed to be factors in the crash.

"Numerous witnesses plus the first assessment from the debris field would indicate that speed was a factor," he said.

The truck had a number listed at the back which people could call if they were concerned about the way it was being driven. CTV Calgary spoke to a call centre operator who said she was on the phone with a complainant who was behind the truck just before the crash.

He complained about the way the truck was being driven. Gina Wilke, the operator who took the call, said the sounds she next heard over the phone still haunt her.

There was a "scream and the crash of the actual (accident). It was that loud," she said.

On the other end of the line, Wilke said the complainant "screamed 'oh my God!' He has just gone through a red light and he has just hit a car, T-boned a car. Call 911. I have to hang up."

C and J Construction, the company which owns the truck involved in the crash, released a statement late Saturday: "At this time of great sorrow, we offer our deepest and sincerest condolences to the family and friends of the victims of this terrible accident (Friday) evening."

The statement went on to say that because of the on-going police investigation, the company will not comment further and will respect the privacy of all those affected.

MacLeod Trail, the site of the crash, is a major roadway that runs from the south of Calgary to downtown.

Slater said weather was not a factor and road conditions were not icy or slick at the time. "It's a tragic situation that reinforces that speed kills," he said.

Tschetter remains in jail and has been charged with the following:

• Refusing to provide a breath sample;
• Five counts of dangerous operation of a motor vehicle causing death.

He is expected to appear in court on Dec. 13.

With a report from CTV Calgary