The Gleno Dam was a hydroelectric dam in Italy that tragically collapsed in 1923, causing widespread flooding and the loss of at least 356 lives. Initially built as a gravity dam but later changed to a multiple arch design to save money, the poor construction quality ultimately led to its failure. The disaster prompted changes in Italian dam design practices, with multiple arch dams falling out of favor. Today, a smaller dam stands in its place, serving as a reminder of the tragic event that occurred almost a century ago.