open access Accident Experience: Iron-Ore Mines, Lake Superior District, 1940-43 Description: Report issued by the U.S. Bureau of Mines discussing the iron-ore mining accident experience in the Lake Superior District. Frequency and severity rates of accidents between 1940 and 1943 are presented. This report includes tables. Date: May 1945 Creator: Cash, Frank E. & Larsen, Reuben D.