We have a pumped hydro facility here in MO. They had a catastrophic failure in 2005 which sent a billion gallons of water flowing downstream, right through a popular campground and the very popular Johnson Shut-ins. Luckily it was at 5:00am in December so no one died. Ironically, someone did die in the construction of the replacement a few years later. Overall a very interesting story, and one I teach my freshmen about.
I think it's quite interesting how important Ameren knew this plant was. Important enough to spend quite a bit of money and build one in the same place as the disaster a few years before.
https://en.wikipedia.org/wiki/Taum_S..._Power_Station