Practical Knowledge, Science and Disasters. The History of Social Science Disaster Research, 1949-1979. During the second half of the twentieth century several US-American social science "disaster research groups" conducted field studies after earthquakes, factory explosions and "racial riots". Their aim was to provide practical knowledge that could be applied in the planning and managing of future disasters of both peace- and wartime nature. In this paper, I will elaborate on how this research goal conflicted with some scientists' aspirations to develop more theoretical knowledge and their own ideals of "scientificity". I will also show how the generated research results came to be 'impractical knowledge', which was difficult or impossible to apply. Furthermore this paper analyzes the scientific practices that were involved at different stages of the knowledge production process and contributed to disaster research's 'precarious' character.