Frank Slide boulder, sedimentary rock, Alberta. This rock is from the site of Canada's worst natural disaster at Crowsnest Pass, Alberta. At 4:10 am on April 29, 1903, 30 million cubic metres of rock fell from Turtle Mountain and covered part of the town of Frank. Out of 600 people living in Frank at the time, only 100 were in the path of the slide – 23 escaped including small children. At least 70 people were killed. This rock was part of the Frank Slide. It is limestone from the Carboniferous Rundle Group (350–300 million years old). The limestone is composed of fossils, including brachipods, horn corals and crinoids. The fossils seen on the right hand side picture are crinoids osicles which are parts of stem of sealilies.