On 9 October 1963, engineers observed trees falling and rocks rolling down into the lake where the predicted landslide would take place. Prior to this, the alarming rate of movement of the landslide had not slowed as a result of lowering the water, although the water had been lowered to what SADE believed was a safe level to contain the displacement wave should a catastrophic landslide occur. With a major landslide now imminent, engineers gathered on top of the dam that evening to witness the tsunami. At 10:39 P.M., a massive landslide of about 260,000,000 cubic metres of forest, earth, and rock fell into the reservoir at up to 110 kilometres per hour, completely filling up the narrow reservoir in front of the dam. The landslide was complete in just 45 seconds, much faster than predicted, and the resulting displacement of water caused 50,000,000 cubic metres of water to overtop the dam in a 250-metre high wave Read more