The town of Frank, Alta., lay sleeping in the shadow of Turtle Mountain on April 29, 1903. But at 4:10 a.m., the side of the mountain fell onto the town. In just 90 seconds, a wall of destruction wiped out homes and entire families. The National looks back at the slide on its 100th anniversary. Experts say it's a matter of time before it happens again.

• In 1901, Henry Luplin Frank – a businessman from Butte, Mont. – founded Frank, a mining town at the base of Turtle Mountain in the Rockies. The town was in the coal-rich Crowsnest Pass in what is now southern Alberta.
• By 1903, about 600 people were living in Frank. It was actually part of the Northwest Territories until Alberta was formed in 1905.

• On April 29, at 4:10 a.m., 30 million cubic metres (82 million tonnes) of limestone fell from Turtle Mountain. It covered 2.67 square kilometres. Many of the boulders were as big as houses.
• About 100 people lived in the slide's path — 70 were killed. Only 12 bodies could be found in the immense rubble.

• The slide destroyed seven cottages, a dairy farm, a ranch, a shoe store, a livery stable, cemetery, two kilometres of the road and CPR rail line, a construction camp and all of the surface buildings for the Frank mine. (Source: Frank Slide Interpretive Centre.)

• The headline of the next day's Toronto Globe blared, "Earthquake rockslide overwhelms Frank, N.W.T." The story continued, "The top of Turtle Mountain was either blown off by an eruption or shaken over by an earthquake."

• Famous tales of the slide include: – Sid Choquette, a brakeman for the Canadian Pacific Railway, raced across the rubble to flag down a passenger train from Lethbridge that was on a collision course with the giant boulders, some bigger than rail cars, covering the tracks. He stopped the train in time.
– The house of Alexander Leitch was hit by the slide but his three young daughters miraculously survived. Marion Leitch, 15 months old, was thrown from the house but landed safely on a pile of hay.
– Seventeen coal miners were trapped but managed to dig their way out 14 hours after the slide.

– Alex Clark was one of three miners who died on their lunch breaks. His wife and six of their children were killed when their home was destroyed. Their daughter Lillian, 15, survived because she worked in Frank's boarding house and had her mother's permission to stay there overnight for the first time.

• Perhaps the most widely told tale was of a baby girl being the town's only survivor. The myth may have been sparked by true stories of at least three girls who survived. Two-year-old Gladys Ennis was thrown from her home and found in a pile of mud. Gladys was the last living survivor of the slide — she died in Bellevue, Wash., in 1995. (Source: Frank Slide Interpretive Centre.)

• The mountain had long been unstable and smaller rockslides were common. The Blackfoot and Kutenai people called it the Mountain That Moves. In the weeks before the slide, miners heard ominous rumblings. (Source: Maclean's magazine.)

• So what spurred the massive slide? Geologists say the mountain itself is unstable. A fault runs through it. And it's likely that large coal mines inside the mountain made it even more unstable.
• In 1911, the government ordered everyone to leave Frank after a study determined Turtle Mountain was still unstable. Many of the townsfolk settled in New Frank, just northwest of the original town. That town, now known as Frank, Alta., is still there.

• Three weeks after the slide, the railway was cleared of boulders and rebuilt. A road was built in 1906. In the 1930s, more of the rubble was cleared for a highway.
• Geologists say the next slide is most likely to occur on the other side of the mountain but cannot say when. At the time of the slide's 100th anniversary, in 2003, nine homes were in the direct path of that possible slide. One resident, Roy Lazzarotto, told Maclean's, "I know a lot of people say they would never live where we do. But to me, it's beautiful here and I love it."

Medium: Television
Program: The National
Broadcast Date: April 29, 2003
Host: Peter Mansbridge, Reporter: Cameron Macintosh
Guest(s): Emilie Berkwin, Monica Field, Arthur Graham, Dennis Makin, Gerry Makin, Robert Stewart
Duration: 6:14
Photo Credits: Canada. Dept. of Mines and Technical Surveys / Library and Archives Canada / C-022991