st basic question in the field: that of defining the phenomenon of study. For theoretical advancement, it is important that researchers begin to develop a consensus about the meaning of disasters and related phenomena. With the rise in international terrorism, one must clarify whether these events are disasters and if so, what kind of disasters. Similarly, in addition to natural disasters, do we include riots, explosions, nuclear power plant accidents, damn collapses, and land subsidence under the same conceptual umbrella? What practical and theoretical differences does it make if the same label is used or not used for such different situations? What is a Disaster? Brings together twelve social scientists representing eight disciplines and seven countries to share their definition and vision of disasters. In the process, a wide range of views are expressed and issues raised regarding the relationship of academic versus practical definitions, the impact of grouping types of disasters in different ways, and the epistemologies on which theoretical growth should rest. The forum provided involves the presentation of each author's views, followed by a discussant's critique, and closed with a response from the author. The editor's close the volume with discussions of the theoretical framework of disaster research and an agenda for disaster research in the twenty-first century.