MONTREAL -- A group of American tourists who were at the front of a massive accident involving 200 cars south of Montreal narrowly escaped injury on Wednesday after blowing snow completely obscured their vision and cars began colliding all around them.

Spencer Jacob and four of his friends from upstate New York had been vacationing in downtown Montreal. About 20 minutes into their drive home, they merged onto Highway 15 and immediately faced a sheet of white. "There was just pure white snow like a whiteout getting blown onto the roads. We couldn't see anything," Jacob told CTV News.

Wanting to be safe, the boys pulled over onto the shoulder, and called police. "So we all just wanted to be safe. So as there were cars coming, everyone was going different speeds so we didn't know if someone was going to hit us, if we were going to hit somebody, so we decided to pull over. And then, the side of my car got clipped by another car coming so that's when I called the police and I was like 'this isn't good," he said. 

Jacob had a hard time explaining to officers where they were, because the New Yorkers weren't familiar with the landscape. But, after about 15 minutes, an ambulance arrived and parked in front of the tourists.

Then, a car hit the ambulance at full speed, Jacob said. It was, ostensibly, the start of a pileup which would injure almost 100 people and kill two.

"Another car came down and just flew into the back of the ambulance. That blocked up two lanes and then another 18-wheeler came and just slammed into that car," Jacob said. "That's when we were like 'this is bad,' and we need to get out of the car. Our doors were pressed against the snow so we had to get out of the windows and run up onto the snowbank and we were just watching." 

The five Americans climbed out their windows and onto a snowbank. "It was straight out of a movie," Jack Sandberg, one of the tourists, said. 

They waved to incoming cars, trying to warn them. "They couldn't see," Jacob said. They could only watch as cars slammed into each other repeatedly. They were also freezing. One of them was in shorts. Snow was up to their waists and they were still too close to the carnage.

"A car came flying in and hit the car to our left and spun and the lights shattered and glass flew over our heads," Jacob said. "Once that happened we had to run up the road."

A police officer picked them up and drove them to the community centre where, later, shuttle buses brought 150 people, many of whom had been injured in the accident.  

It was reassuring to receive medical help and food, Jacob said. Stretchers and paramedics passed in and out of the community centre, taking the injured to the hospital. As of Wednesday evening, the Americans were among the only people left there, most others having been picked up by family members. 

A friend's parent had rented a large car and would pick them up, he said. But the images they witnessed on the snowbank -- the cars careening into each other, their drivers unaware of the danger ahead -- would stay with them. 

"I turned my back to it," Jacob said. "I just couldn't watch it or hear it any more because it's just so horrific that people don't know where they're going and they just crash into a car."

With files from Andrew Brennan.