It was 109 years ago this week, in the early hours of April 29, 1903, that the Frank Slide—the deadliest rock slide in Canadian history—claimed the lives of 90 Albertans.
Back then Frank was a bustling mining town of 600 residents. Today it is a quiet community of 200 in Southern Alberta’s Crowsnest Pass.
The area continues to bear the scars of that fateful night, when the tip of Turtle Mountain detached from its base and plummeted to the ground.
In 90 seconds, 82 million metric tonnes of rock came crashing down, leaving destroyed homes, businesses, and lives in its wake. When the dust cleared, the rubble covered two kilometres across the valley.
“Scientists have actually calculated that if you took all the rocks that fell off the mountain you could make a one by six-metre wall that could go all the way across Canada, from Victoria to Halifax— that’s how much rock fell off in the Frank Slide,” says Joey Ambrosi, interpretation-education officer at the Frank Slide Interpretative Centre.
“In the path of the rocks there were about 110 people. Of those, about 90 were killed.”
There are dozens of homes in the area that could one day be impacted from another major slide, however.
But an extensive system was put in place in the last decade that would give residents months, if not years, of warning if a section of the mountain were to become unstable.
The Alberta Geological Survey has installed a network of sensors on the mountain as an early warning system that would alert researchers of irregular movement. Cracks, degree of tilt, and spaces in the rock are also monitored.
The real-time data stream from the network provides insight into the mechanics of the rock mass, as well as how weather affects its movement. The data are also analyzed to identify patterns that could predict future changes in the mountain.
Scientists predict an area known as South Peak—five million cubic metres of rock—is the next likely piece to fall, and would be about 1/6 the size of the original slide, threatening a dozen homes nearby.
Ambrosi says if its current rate of movement remains—equivalent to the thickness of a penny every year—South Peak will likely not fall for thousands of years.
“It’s not just going to grow from what it is now to instantly falling tomorrow, because it’s fairly stable now and it would have to move into a position that it’s not very stable,’ he said.
The cause of the original slide has been blamed on a host of factors, including the mountain’s continuous movement which eventually formed precarious vertical rock slabs, coal mining inside the mountain, and a particularly wet winter with a late April freeze.
Myth vs. Reality
The Frank Slide story has captivated people around the world for over a century. Ambrosi says about 100,000 tourists come to see the rubble every year, which looks much the same as it did minutes after the tragedy.
He thinks people remain interested in the slide not only due to its sensational nature and the awe-inspiring sight of the rubble, but because of the human stories that emerged from the disaster and the incredible resilience of the town.
“After the slide came down, within three months they had the coal mine working again. The town grew from 600 people to 1,000 people. It didn’t just scare people off,” he says.
So many legends have been passed around about the night of the slide that myth has blended with reality.
A common misconception is that Frank was completely buried by the slide, but although the town suffered damage and destruction, only the eastern outskirts were completely covered by the rocks.
Another famous story that has been written into books, plays, and songs was that the “lone survivor” of the slide was a baby girl, found in the rubble the next day and named Frankie Slide.
Ambrosi says the lone-survivor myth may have originated from a story about a particular area near the town that was directly hit by the slide. Of the 23 survivors in the area, three were young girls who were the only survivors in each of their families.
One, 15-month-old Marion Leitch, was thrown from her house only to land safely on a pile of hay.
Another inspiring survival story is the tale of 17 miners who were trapped inside the mine when the mountain fell. The tunnels remained intact but all the entrances were blocked, so the miners set about digging their way out.
All 17 men popped out of the rubble one-by-one that evening, much to the town’s amazement.
Another enduring legend is that local aboriginals had long warned European settlers not to go near Turtle Mountain.
The Blackfoot and K’tunaxa peoples had oral traditions that referred to Turtle Mountain as “the mountain that moves,” and had long refused to camp in the area that was later impacted by the slide.
According to the Frank Slide interpretive centre website, prehistoric people in the area likely saw cracks and fissures along the summit ridge and left pictographs on adjacent mountains to warn others of the danger. They may also have observed seasonal rock falls and developed a keen awareness of the risks.
Ambrosi says these are lessons from the tragedy that can still be applied today.
“Some of the lessons were that you shouldn’t be so greedy, and just be charging in to take everything out of the ground without having a good look around at where you’re doing it, and what you’re doing to it,” he says.