The truck driver killed in a fiery crash when his semi-trailer went off an Edmonton overpass is being remembered as a "great friend" with a "big smile."

Friends have identified Mark Santos, 25, as the man who was behind the wheel of the truck that drove the wrong way down the busy Yellowhead Trail freeway early Monday afternoon before hitting a guardrail, rolling off the overpass onto the railway tracks below and bursting into flames.

Mark Santos, 25, died when his semi went off an Edmonton overpass.
(CBC)

Marcie Plante-Bennett, who used to babysit Santos, and her sister created a group on the popular social networking site Facebook where friends could share stories about Santos.

She told CBC News they started the group "to show him how much we loved him and let his family know that we are thinking of them, 'cause we couldn't be with them."

People on the site share stories of their friendship with Santos, a hockey fan, and express their sympathy for his girlfriend, Sherri, and her children. He is widely described as a "great friend" who will be sorely missed.

Bennett said Santos's sister thanked her over Facebook for starting the group.

His family told local media that the accident may have been caused by a diabetic reaction. Santos had Type 1 diabetes and sometimes suffered severe hypoglycemic reactions that caused seizures and blackouts, they said.

Police have not positively identified Santos as the victim and are still investigating the cause of the crash.