oldbeek,

A friend of mine ran a job enlarging the Pear Blossom Pump Station in the early '90s. He was working for the Italian company who bought out S. J. Groves (once upon a time Caterpillar's largest customer - owned lots of scrapers.) I got to visit the project a couple of times. That is indeed a big hole in the ground. While he was there, the roof of the older plant caught fire and melted tar dropped down into the pump motors below. It was quite a mess. I don't remember what caused it but it happened during the night when nearly everyone was gone. I think a new roof was being put on and the roofing contractor got dinged for the cause. The roof was not part of my friend's project.

Same owner as the Oroville Dam. I wonder if there is a common theme here?

JanM