30 million cubic metres of limestone broke free from the mountain and crashed down towards the sleeping populace of Frank.
In a mere minute and a half a landslide one kilometre wide and 425 meters deep obliterated a large portion of the town and killed an estimated 76 of the 100 people that lived in its path. A further 23 were injured and some 17 unfortunate miners trapped inside the mine.
The massive rock fall covered the Crowsnest River that runs through the valley, damming it completely and destroyed 2 kilometres of the Canadian Pacific Railway and road. Almost all of the lucrative mine’s surface infrastructure was annihilated. A construction camp, dairy farm, shoe store, houses, a ranch, stables and even the cemetery were all buried beneath the huge weight of the slide.
The rockslide took place shortly after 4:00 a.m. on the morning of April 29, 1903. Millions of tons of limestone rock slid down off the northeast face of Turtle Mountain. The rock covered the entrance to the mine and much of the town in less than two minutes. The slide buried everything in its path. Rocks crossed the valley and landed 120 metres (400 feet) up the opposite slope. Parts of the town escaped the slide, but the limestone covered almost 2 square kilometres (1.2 square miles) to an average depth of 13.5 metres (45 feet).
Seventeen miners working on the overnight shift inside the mine were trapped underground. As rocks covered the mine entrance, they were forced to dig out through 6 metres (20 feet) of coal and 2.7 metres (9 feet) of limestone boulders. The effort took them 13 hours. Three mine workers who were working above ground were killed by the slide. In total, about 70 people were killed out of a population of approximately 600. Only 12 bodies were actually recovered and the list of the dead remains incomplete.
Frank, Alberta is a coal mining town in the Crowsnest Pass, Alberta. On April 29, 1903, at 4:10 a.m., 90 million tonnes (30 million cubic metres) of limestone crashed from the east face of Turtle Mountain and covered approximately three square kilometres of the valley floor. The slab of rock that broke free was approximately 650 m high, 900 m wide and 150 m thick. The slide dammed the Crowsnest River and formed a small lake, covered 2km of the Canadian Pacific Railway, destroyed most of the coal mine's surface infrastructure, and buried seven houses on the outskirts of the sleeping town of Frank, as well as several rural buildings. Frank was home to approximately 600 people in 1903; it is estimated that 90 of the roughly 100 individuals in the path of the slide were killed.
The town was evacuated, but people were soon allowed to return and both the mine and the railway were back in operation within a month. The town of Frank continued to grow, until a report on the mountain’s stability resulted in the provincial government ordering the closure of the south part of the town in 1911. Studies and monitoring continue today.