1917 Treadwell Mine cave-in remembered a century later

This photo taken April 22, 1917, shows a massive sinkhole that opened up as the Treadwell Mines collapsed and filled with seawater. (Photo courtesy Alaska State Library, from the Harry F. Snyder Photograph Collection)
This weekend will be the centenary of a massive cave-in that flooded much of the Treadwell Mine complex.
At its peak the mines on Douglas Island were among the largest gold mining operations in the world and helped shape the development of Douglas and Juneau.http://s3-us-west-2.ama