Select the passage that has a more matter-of-fact tone.
Underground water, percolating through porous riverbeds, will eventually bring about
a collapse. The rocks forming the slopes of the mountain will, from time to time,
give and slide into the valley.
There came a rending crack, terrifying in its loudness. A tremendous tower of ice
leand slowly outward and then roared downward, falling in a solid piece like a
demolished skyscraper.
Adapted from James Geikie, Fragments of Earth Lore and Rex Beach, The Iron Trail