Frank Slide Disaster

Date: April 29, 1903 • Location: Pincher Creek, Canada

A rockslide buried part of the Canadian mining town of Frank under 110 million tonnes of rock, killing around 70 people.

The Frank Slide was a massive rockslide that buried part of the mining town of Frank in the District of Alberta of the North-West Territories, Canada, at 4:10 a.m. on April 29, 1903. Around 44 million cubic metres/110 million tonnes of limestone rock broke off from, and slid down, Turtle Mountain. Witnesses reported that within 100 seconds the rock reached up the opposing hills, obliterating the eastern edge of Frank, the Canadian Pacific Railway (CPR) line and parts of the coal mine. It was one of the largest landslides in Canadian history and remains the deadliest, as between 70 and 90 died, most of whom remain buried in the rubble. The cause of the slide is unknown but multiple factors may have helped cause the slide: Turtle Mountain's structural formation was unstable and had been for some time; coal mining operations may have weakened the mountain's internal structure; a wet winter and cold snap on the night of the disaster may have contributed.