The Monte Crenone rock avalanche of 1513 is well known on the southern side of the Alps because in 1515 it generated the largest inundation that has occurred in Switzerland in the Common Era, the Buzza di Biasca. New geological and historical observations allowed the setup of a numerical model of this major event, permitting a better definition of the chain of consequences that affected the alluvial plain of the river Ticino from Biasca to Lake Maggiore between the 16th and the 19th century.