On December 1, 1923, at around 7:30 a.m., the tragedy occurred in Val di Scalve, in the province of Bergamo. 356 confirmed deaths and even today there is no certainty as to why the dam collapsed. It was December 1, 1923 when the Gleno dam collapsed in Val di Scalve, in the province of Bergamo. There were hundreds of deaths: 356 confirmed deaths. A massacre, a forgotten Vajont. And a collapse about which even today, 100 years later, there is no certainty. The ruins of the dam are still there in the middle of the mountain, majestic and ghostly, with that enormous gash that looks out over the valley. A gigantic wound that tells of a tragedy completely erased from the memory of our country. 7:30 a.m. The roar, the wind and then the mass of water that overwhelms everything and everyone. It was around 7:30 in the morning when the structure collapsed in the central part and six million cubic meters of water began to flow along the valley, sweeping away entire villages in Val di Scalve: Bueggio, immediately below the dam, and then Dezzo; Mazzunno and Corna di Darfo, in Valle Camonica (province of Brescia), until reaching Lake Iseo. All in 45 minutes. Why did it collapse? Even today it is difficult to say with certainty why the dam collapsed, as also emerges from a study conducted in the last year by the University of Bergamo (which on the occasion of the centenary of the tragedy published a book on Gleno: «A partire da quel che resta»). There are various hypotheses on the reasons for the disaster: a change in project during the works without the necessary authorizations, construction errors, small earthquakes or, the most accredited, the use of poor quality materials. All possibilities, but there is no definitive answer. During the trial, a bomb attack was also hypothesized, there are testimonies that tell of a roar and defense reports that support this idea but, again, no confirmation. The factsWork on the dam began in 1916 and ended in 1923. A cutting-edge work for the time. Initially, the project included the construction of a gravity dam, then a change on the fly to one with multiple arches. The final result was an imposing structure: 260 meters long at 1500 meters above sea level. A work desired and built by Virgilio Viganò, owner of cotton mills that needed low-cost hydroelectric energy. On October 15, 1923, the basin filled for the first time, it was a very rainy period and numerous water leaks occurred from the dam. This alarmed the inhabitants of the valley. Yet, on October 22, the head of the Bergamo civil engineering department goes up to the dam for an unofficial test and asks the designer, engineer Santangelo, if he feels calm. "Very calm" is his reply. A little over a month later the dam collapses. The trialA year later the trial begins. The defendants... (Gian Marco Alari / CorriereTV). Watch the video on Corriere: https://video.corriere.it/cronaca/cro...