CMS 9616429 Olson The twin earthquakes of September 19 and 20, 1985 that devastated central zones of Mexico City remain one of the great urban catastrophes of the late 20th century. One of the most significant characteristics of the disaster was the breath, depth and duration of popular response, especially the emergent organizations that focused on a variety of post- earthquake problems. This project analyzes the life cycle of two sets of such organizations. These include groups and organizations that transformed in the years after the earthquake and survive to this day, and those that also emerged out of the earthquake and were active during the emergency phase but disappeared at various points during recovery and reconstruction. Aside from being an interesting phenomenon for researchers to study, such groups represent an important resource during the time of disaster. Thus a practical implication of developing an improved understanding of the origin, nature and changes such organizations undergo is that it will give emergency management practitioners in the U.S. and elsewhere insight on how to more effectively incorporate them into their disaster planning and subsequent emergency activities. The multiple data sources for this study will include interviews, archival materials, and direct observation.