EDMONTON. — Friends and relatives says diabetes may have played a role in the actions of a semi driver who died when his rig crashed and exploded after barrelling down the wrong lane of an Edmonton-area highway.

Dozens of terrified motorists were forced to swerve or drive into the ditch Monday to avoid the semi driven by Mark Santos, 25, of Grande Cache.

The semi eventually plunged over the guard rail of a bridge and onto railroad tracks below, exploding into a massive fireball. No one else was hurt.

Witnesses appeared torn over whether Santos was purposely trying to hit oncoming traffic or trying to avoid it.

“He looked angry, he looked mad, he looked zoned out,” said William Acevedo, who had to swerve to avoid being hit.

But Carrie Balkwill said in her opinion, the driver was doing his best to be as noticeable as possible and avoid other motorists.

A family friend who didn’t want to be named told the Edmonton Sun that Santos had Type 1 diabetes since he was a child and has been in a “few situations where he’s blacked out” because of the condition.

The friend was horrified at any suggestion his buddy was trying to hit other cars.

“Mark would never hurt anybody,” said the man. “He would never have done this to anyone intentionally.”

Santos’s brother Jordan confirmed his medical condition and said he had problems with it in the past.

“When he goes low, he doesn’t remember anything, he doesn’t know what to do, he’s just not there,” Jordan told CTV Edmonton. “He’s just someone that’s breathing with his eyes open.

“He would not hurt another human being at all. I know him and he’s the most respectful guy I’ve ever met in my life.”

Type 1 diabetics can suffer from a loss of consciousness for minutes or hours, said Dr. James Shapiro, a diabetes expert.

“It begins with sleepiness and disconnection with the surroundings and eventually if the blood sugar falls dangerously low, the person loses consciousness.

“We have treated 100 patients with severe hypoglycemia. In other situations, we have come across many patients who have had motor vehicle accidents where they are not responsible for their actions.”

Truck driver Doug Fox said during the incident, other drivers tried to contact Santos but never got a response. “You could hear the guys on the CB hollering at this guy that he’s going the wrong way,” said Fox.

“Nothing came back at all. It’s weird. Unless the guy was really confused or maybe having medical problems or something.”

Mark Santos had been a semi driver for six years and was working for Linmar Holdings out of Winfield when he died.

Edmonton police spokeswoman Karen Carlson confirmed the investigation would look at any medical or psychological conditions Santos may have had.