Construction of a hydroelectric dam to exploit the river Gleno in the the Valle di Scalve (Scalve valley) began in 1916, but the project was immediately cursed by poor materials and poor workmanship. On top of that, due to funding problems, the plan changed from the original idea of a gravity dam to a multiple-arch dam while the work was still in progress, resulting in a mixed-type dam.

Just after its completion, heavy rains filled the reservoir, and several leaks caused concern among the inhabitants of the valley below. Sure enough on December 1, 1923, at 7:15 in the morning, the tragedy happened. The central section collapsed, causing a mass of 4.5 million cubic meters of water to pour into the villages in the Scalve valley. The official death toll counted 356 lives lost as a result of the flood, as well as massive damage to roads, bridges and buildings.