Storm Alex hit Western Europe from 1 to 7 October 2020, becoming one of the most extreme climatic events in the current decades. The storm caused widespread destruction, especially in France and northern Italy. In Piedmont exceptional rainfall triggered landslides, floods and the collapse of numerous critical infrastructures including bridges and state roads, highlighting serious territorial and systemic vulnerabilities. The first section of this thesis aims to analyse the event with particular focus on the most affected areas in Piedmont, through a multidisciplinary approach that combines hydro-meteorological analysis, reconstruction of infrastructure damage, examination of the causes of failure and assessment of the responses made before and during the event.