For several days now, the western slope of the Andes has been drenched by relentless rain. The thin layer of soil covering the bedrock is so saturated that it can hold no more water. Thousands of tiny streams race downhill, weaving together like the veins of some enormous creature into roaring rivers that carry life-giving water and tons of sediment toward the foothills. On one particularly steep slope above one such river, a crack suddenly appears. The roots of countless plants, which for centuries have collectively anchored the soil to the mountainside, can no longer resist gravity. Tons of rock, earth, and vegetation suddenly slide downward with a deafening roar, plunging into the depths on a giant natural landslide before coming to rest in the foaming river below.
