At 4:10 in the morning on April 29, 1903, a giant sheet of rock broke away from the side of Turtle Mountain
, in the Canadian Rocky Mountains
, and slide directly into the unsuspecting mining town of Frank
. It is estimated 82 million tonnes of limestone
crashed down from the mountain. Of the 600 residents of Frank, about 70 were killed and many more lost their homes. The railway line through the town was covered and it took over three weeks to rebuild. A road wasn't cleared through the debris until 1906.
The rock covered over three square kilometers and the cause of the slide is still unknown. Water and ice eroding summit cracks and severe weather conditions may have contributed to the disaster, and underground coal mining may have also contributed.
Frank was located in the Crowsnest Pass, in Alberta, Canada, and is now abandoned except for a visitors centre.