This research aims to investigate whether disaster response systems have the foundations needed to self-organize and overcome the uncertainties present in post-disaster environments. Drawing upon contributions from the resilience, network governance, and complex adaptive systems literature, this article presents the findings of an investigation into the disaster response system that operated in Indonesia after the 2004 Indian Ocean Earthquake and Tsunami. Network data, comprised of organizational actors and their interactions, were collected from newspaper articles and situation reports published between 26 December 2004 and 17 January 2005. These data were transformed into a series of twenty-two relational matrices and processed with network analysis software. Three network measures, namely, density, diameter and components, were computed and plotted by date to evaluate the development and structural evolution of the tsunami response system. The findings indicate that the disaster response system experienced structural change. While additional research is needed to validate these ﬁndings, future research should explore the mechanisms that drive self-organization in post-disaster environments, as well as the steps policy-makers can take to design and promote self-organizing disaster response systems.