mining is a dicey business. the area i live was once mined for coal and clay ( for bricks ) and there are active mines not far from where i live. we hear of cave ins, explosions, etc every few years...the most famous was quecreek in 02 where they got the miners out by drilling down and making a 1 man elevator. but those arent the only mine disasters...we have houses swallowed up when some of the closed mines collapse...and thre are several mine fires that have been burning for years... interesting bit of history you shared nuuuuman thanks