A reconstruction expert says the cement truck Daniel Tschetter was driving was going 105 km/h when it hit a stopped car.
The crash happened in December 2007 at the intersection of Macleod Trail and 194 Avenue South.
The cement truck smashed into the back of a car while it was stopped at a red light.
Fourty-year-old Chris Gautreau, his daughters nine-year-old Alexia, six-year-old Kiarra, his girlfriend Melania Hovdebo and her 16-month-old son Zachary all died at the scene.
Tschetter is charged with five counts of manslaughter and five counts of criminal negligence.
On Thursday, the police officer involved in the accident's reconstruction says the crash was so bad the two vehicles basically became one object.
Cst. Robert Gauvin also testified that Tschetter did not hit the brakes until he hit the car.
The two vehicles slid nearly a quarter kilometre down the road before coming to a stop.
The mother of Alexia and Kiarra listened to the testimony on Thursday. "They were my life. They were all that I had. It's just hard, this is just hard," says Previna Jiawan-Gautrau.
The trial continues in Calgary on Friday.
