One of the two people killed by a runaway dump truck Tuesday afternoon in Coquitlam was a recently married father-to-be, according to his heartbroken family.

The victim has been identified on social media as 32-year-old Bobby Vanderhoef, a Maple Ridge resident who just married his partner Amanda in May.

"You were so excited to become a dad and this baby won't have the chance to know you," his grieving wife wrote on Facebook.

"I want it to be a dream and I want you to grab and hug me and tell me it will be ok. I love you so much and I promise to take such good care of your little one."

Their child is due in January.

Vanderhoef's pastor, Jon Morrison, who presided over the couple's wedding, told CTV News the deceased was known as a loyal friend who would do anything for the people he loved.

"He would've been an amazing dad," Morrison said. "It's very sad for us as Amanda now has to work through this. But she will have support, and we have to be there as a community."

Mounties have confirmed the dump truck was unoccupied when it rolled off a construction site on the Riverview lands and went barreling downhill toward the Lougheed Highway during rush hour.

Witness Kelsey Joy Gordon, who just a few cars behind the carnage, described watching the construction vehicle plow into traffic as the "scariest thing [she's] ever experienced."

"I was like, what is this guy doing? Why is he going this fast? Turns out no one was in it," she said.

The earthmover struck three vehicles before coming to a stop on top of a sedan. Two people were killed and another six were sent to hospital with minor injuries.

Officials have not confirmed the identities of the deceased, only that one is a man in his 30s who had been driving the dump truck and the other is a woman in her 60s who was a passenger in one of the vehicles that were struck.

Witnesses told CTV News they saw a man running after the commercial vehicle as it rolled into traffic, which may have been a futile attempt to stop it. Yashar Karimi said he saw the dump truck take out a gate and run a man over.

"I looked up and I see the truck rolling down and around a guy," he said.

The cause of the deadly crash is still under investigation by the Coquitlam RCMP's Coordinated Collision Investigation Team, which spent Wednesday interviewing witnesses and continuing to process the accident scene.

The earthmover will also undergo an inspection to determine if mechanical issues are to blame for the tragic collision.

With reports from CTV Vancouver's Penny Daflos, Sarah MacDonald and Nafeesa Karim