At 4:10 a.m. on April 29, 1903, approximately 80 million tonnes of limestone crashed down from the summit of Turtle Mountain and buried a portion of the sleeping town of Frank, a community in Crowsnest Pass, Alberta. In the greatest landslide to ever occur in North America, a chunk of rock face 500 feet deep, 1,400 feet high, and a kilometer wide fell in 100 seconds.
The slide completely destroyed a 2 kilometer section of the Candian Pacific Railway. A brakeman for the Canadian Pacific Railway, Sid Choquette, had to race across the rocks to stop an approaching passenger train before it collided with the slide. (The buried section of railway was rebuilt 3 weeks later). The slide destoyed the surface buildings of the Canadian American Coal and Coke Company, two ranches, part of the Frank and Grassy Mountain Railway line (which runs to the historical town of Lille), a construction camp, and livery stables, as well as three-quarters of the homes in Frank.
The majority of the town's population (about 600 poeple) were a stone's throw beyond the area buried at the time - many just by chance. At least 100 people were in the slide's path. Of those, only 23 survived. Those that did were mostly children. Of the 76 known and listed dead, only 12 bodies were ever recovered.
The slide occured as a result of Turtle Mountain's unstable structure, supplemented by the removal of a quarter million tons of coal between 1900 and 1903. For seven months prior to the slide, men working in the mines had reported weird activity in the mountain. Large timbers had cracked under pressure, coal had "mined itself" at night, and some mornings, the mine had pitched as though it were a boat at sea, being tossed by giant waves. Even before the coming of the miners, the Blackfoot and Kutenai Indians had described Turtle Mountain as "the mountain that moves".
Still, when the slide occured, the mine was not severely damaged. True, some tunnels were pinched, rocks fell from the roof, and ventilation was blocked, but the entire crew of 17 men who were underground at the time managed to dig themselves out after 14 hours.
It seems that ice was the direct cause of the slide. The previous winter had left an unusually large icepack on Turtle Mountain, which had melted more quickly than usual in April, because of unseasonably warm temperatures. The water flowed into the fissures already there on the mountain. On April 28th, 1903, it froze.