Erto e Casso (PN, Friuli Venezia Giulia, Italy)
On 9 October 1963 at 10:39 PM, a landslide of about 260 million m³ of forest, earth, and rock fell into the reservoir created by the Vajont Dam (still one of the highest concrete dams in the world, in Belluno province) at up to 110 km per hour (68 mph). The resulting displacement of water caused 50 million m³ of water to over-top the dam in a 250 m high wave. Despite this, the dam's structure was largely undamaged.
The flooding in the Piave valley destroyed the villages of Longarone, Pirago, Rivalta, Villanova and Faè, killing around 2000 people and turning the land below into a flat plain of mud. Many small villages in the territory of Erto e Casso and the village of Codissago were largely wrecked. Estimates of the dead range from 1900 to 2500 people, and about 350 families lost all members. Most of the survivors had lost relatives and friends along with their homes and belongings.
Immediately after the flood, governement and most of the italian newspapers depicted the tragedy as an unexpected and unavoidable natural event and marked as jackals journalists and politicians who dared to say that the landslide was largely predictable. But soon enough it was clear that governement, dam builders and owners (energy producers and providers) and engineers purposely ignored irrefutable proofs of the great instability of Mount Toc (which name means in local dialect “crumbling”).
Most of the survivors were moved into a newly built village, Vajont, 50 km south east on the river Tagliamento plain. Those who insisted on returning to their mountain life in Erto e Casso were strongly discouraged. Longarone and other villages in the Piave valley were rebuilt with modern houses and factories.