being used as a battering ram.

"They'll bring the whole mountain down on us!" cried Tim, springing
forward.

But even as he spoke, and before he had moved two feet, that catastrophe
seemed at least to have begun. The prop gave way: the light at the
entrance was at once blotted out; the air was filled with terrifying
roaring echoes. There followed a succession of crashes, the rolling of
rocks over each other, the grinding slide of avalanches great and small.
We could scarcely breathe for the dust. Our danger was that now the
thing was started it would not stop: that the antique and inadequate
supports would all give way, one bringing down the other in succession
until we were buried. Would the forces of equilibrium establish
themselves through the successive slight resistances of these rotted,
worm-eaten old timbers before the constricted space in which we crouched
should be entirely eaten away?

After the first great crash there ensued a moment's hesitation. Then a
second span succumbed. There followed a series of minor chutes with
short intervening silences. At last so long an interval of calm ensued
that we plucked up courage to believe it all over. A single stone rolled
a few feet and hit the rock floor with a bang. Then, immediately after,
the first-deafening thunder was repeated as evidently another span gave
way. It sounded as though the whole mountain had moved. I was almost
afraid to stretch out my hand for fear it would encounter the wall of
débris. The roar ceased as abruptly as it had begun. Followed then a
long silence. Then a little cascading tinkle of shale. And another dead
silence.