Dam failures can be truly horrific. When the South Fork Dam failed and flooded Johnstown, the floodwaters smashed a bunch of people, a barbed wire factory and various other debris into a stone bridge (which still stands today.) The debris, a tangle of wood, people (many still alive), and twisted metal, then caught fire and burned for days, killing dozens. They had to use dynamite to clear the wreckage.

https://en.wikipedia.org/wiki/Stone_Bridge_(Johnstown,_Penns...