Avondale Mine Disaster. On September 6, 1869, a fire broke out at the nearby Avondale Colliery, trapping the miners. The eventual death toll was 110. This included five boys between the ages of twelve and seventeen, and two volunteers who were suffocated while attempting rescue. As a result of this disaster, Pennsylvania's General Assembly enacted legislation in 1870 which was designed to enforce greater safety in the industry.