This book is the accomplishment of three young, enthusiastic, and highly qualified scientists, whom I wish to congratulate: They have ably put this fascinating yet catastrophic natural process in the spotlight. Although poorly known before the 1980 Mount St. Helens eruption, debris avalanches are now recognized as common events in the lifespan of stratovolcanoes. The editors assembled an amazing pool of scientists, who have devoted most (if not all) of their academic careers to understanding this awesome volcanic process. Given our growing awareness of the hazard that volcanoes pose on their surroundings, this contribution constitutes a very useful tool to volcanic monitoring, inasmuch as it encompasses our current understanding on debris avalanches as well as the unknowns that should be the focus of future studies.