Yes, the pond was part of a series of settling ponds for waste from a ferro-alloys plant. We were building new ponds and cleaning out the overflow channel from the ponds. This pond was full of sludge and the dikes were built up over the years using flyash and whatever else they had handy. I had warned the operator to watch for any sign of dike failure, like cracks. Unfortunately, when he saw the crack appear under the machine, it was too late. This happened in the mid 70's.
The reason for the new ponds, was that an old pond dike failed, taking 3 draglines with it. Our company then got the task of designing and building new settling ponds. The whole property was very unstable place to work. I will have to see if I have any photos of the 3 draglines turned over in the old pond.
Jeff