Dammit! I was totally not paying attention and almost got buried alive under a ton or two of loose stone.
Just like it’s dangerous to dig down it is also dangerous to dig straight up and I stood right under an area that I was cleaning out.
The good news, if you can call it that, is that Operation Dig Toward The Mountain is succeeding by accident. Every time I think one vein of ore has petered out, another one appears.