More than 50 years ago, a tremendous thunderstorm in South Tyrol had transformed, within a short time, peaceful brooks into devastating torrents. Whole villages were flooded, houses were destroyed, and people were killed. The memory of those horrible days is still alive in the time witnesses and affected people. They recall their traumatic experiences and their helplessness due to their limited technical means. Six years later, in 1972, the lining of brooks and rivers was started to a great extent. People have learnt from this disaster and nowadays there is a vivid international exchange of information in order to be able to face future thunderstorms in a better way.