The changing demographic landscape of the United States calls for a reassessment of the societal impacts and consequences of so called "natural" and technological disasters. An increasing trend towards greater demographic and socio-economic diversity (in part due to high rates of international immigration), combined with mounting disaster losses, have brought about a more serious focus among scholars on how changing population patterns shape the vulnerability and resiliency of social systems. Recent disasters, such as the Indian Ocean Tsunami (2004) and Hurricane Katrina (2005), point to the differential impacts of disasters on certain communities, particularly those that do not have the necessary resources to cope with and recover from such events. This paper interprets these impacts within the context of economic, cultural, and social capital, as well as broader human ecological forces. The paper also makes important contributions to the social science disaster research literature by examining population growth, composition, and distribution in the context of disaster risk and vulnerability. Population dynamics (e.g., population growth, migration, and urbanization) are perhaps one of the most important factors that have increased our exposure to disasters and have contributed to the devastating impacts of these events, as the case of Hurricane Katrina illustrates. Nevertheless, the scientific literature exploring these issues is quite limited. We argue that if we fail to acknowledge and act on the mounting evidence regarding population composition, migration, inequality, and disaster vulnerability, we will continue to experience disasters with greater regularity and intensity. (Contains 8 figures and 2 notes.)