One of the Worst Man-Made Disasters in History

Vajont Dam. On 9 October 1963, during initial filling, a massive landslide caused a man-made megatsunami in the lake in which 50 million cubic metres of water overtopped the dam in a wave 250 metres (820 ft) high, leading to 1,910 deaths and the complete destruction of several villages and towns.

The construction company and the Italian government initially disregarded early warning signs and reports describing the geological instability of Monte Toc on the southern side of the basin. The eventual attempt to safely control the landslide by lowering the lake level was too late. The dam remained almost intact and two thirds of the water was retained behind it, but the landslide was much larger than expected and the impact brought massive flooding and destruction to the Piave valley below.