This photo is of the Pine Brook shaft subsidence in Scranton 1982. While breaking up the cap on the top of the shaft, the retaining walls below also cracked, and gave way. Compounding this problem is the area was called the " sandy banks area". On account of the depth of sand deposited there millions of years ago by the nearby Lackawanna river. So just like digging a hole in sand, the sides always give way. The same happened here when the retaining walls gave way. The hole widened to 10 times the size of the shaft. Unfortunately a worker was in the wrong spot, and got sucked in when the walls collapsed.
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