A G4S armoured vehicle collided head-on with a pickup truck Tuesday on Highway 63 while on a routine trip between Edmonton and Fort McMurray.
The driver of the pickup was also killed.
Katie McLeod, a spokeswoman with G4S in Toronto, said a second security guard inside the armoured vehicle was not seriously injured. He was treated and released from hospital.
Counselling is being made available for co-workers at the company's Edmonton office, she said, adding it's the second time in two years that they have been in mourning.
Three G4S guards were shot and killed by a fellow crew member in June 2012 as they were reloading ATM machines at the University of Alberta. Another guard who was shot in the head survived.Story continues after slideshow
"To have both horrible instances occur within the same office is just doubly tragic," said McLeod.
"In this industry, it's very much a team environment, so even though we're across the country, everybody feels as a member of the team."
She identified Rod Whalen, 60, as the employee who died in the crash. He had been with the company for more than 15 years, had three daughters and was engaged to be married.
McLeod said she was surprised someone riding inside an armoured vehicle could have received fatal injuries. The vehicles are sturdily constructed — built like tanks, she said.
RCMP described the road as icy at the time of the crash.
Highway 63, the main link between Edmonton and the oilsands region, has become notorious for fatal crashes in recent years.
The provincial government is working to twin the highway in the hope of making it safer.