I have no information on the accident for Henry Schwenn Jr, died 1902Sep, at the Calumet & Hecla Copper Mine in Calumet county.
Calumet Mine Dickinson county MI Latitude 455754N Longitude 0875003W Geological Survey Map Name Felch
Annual Report Mine Inspector, Dickinson Co., Michigan (first report 1901) Library Call No. TN805.M5 D3
In the state of Michigan, the best possible source for these reports are the Michigan State University library in Lansing, the Michigan Tech University library in Houghton http://www.lib.mtu.edu/mtuarchives/
, the Michigan Library and Historical Center in Lansing and the University of Michigan Bentley Historical Library in Ann Arbor. These reports may not only contain names and details for fatal accidents, but also cover strikes, details of mining operations at specific mines, location of the mines, pictures, production and operation details for specific mines.
A newspaper article may also be a good source.
Perhaps you can find help on this web site: http://www.linkpendium.com/
“Mining Accidents U.S., Canada, New Zealand and Australia”