Annual Review 2008 - Hyposwiss Privatbank AG

One rockslide, numerous causes
For decades leading up to the disaster, the people living in the
region had been warned that, one day, the mountain was going
to collapse into the valley. But no-one could have imagined the
magnitude of the disaster. As it happens, the village of Goldau
had been built on the ruins of a prehistoric landslip: history was
to repeat itself. The foundations for the catastrophe were laid
25 million years before, during the ice age, when the Reuss glacier
hollowed out the foot of the Rossberg mountain. This left the
upper layers without any support. After several years of heavy
rain, the Rossberg was saturated right up to the summit. On
2 September 1806, the rock could no longer withstand the
pressure of the water and ripped apart. The entire slope, 80 metres
deep, started sliding downhill. Today, even with the facts before
us, it’s hard to imagine such a thing really happening.