1
They bulldoze the debris, dumping it into nearby valleys.
2
The leftover material is spread into nearby valleys.
3
The 1919 eruption disgorged a crater lake into nearby valleys, drowning 5,500 people.
4
Mining companies clear forests from mountaintops, dynamite the peaks, excavate buried coal, and dump the waste into nearby valleys.
5
When the ash combined with lake and stream water, the surging volcanic debris, or lahar, stormed down nearby valleys wreaking havoc.