This article applies complex evolving systems theory (CES) to investigating the governance factors affecting rebuilding in the wake of the 2004 tsunami in Sri Lanka. It also examines the crucial processes of co-operation between the various governance actors (public, market and civil society) in the aftermath of the disaster. The main focus is on the horizontal integration in the process of service delivery at the district level during the rebuilding stage, and on explaining the nature and extent of collaboration in the delivery of services needed for the survivors to build their new lives. Our observations suggest that influence, incentives and the power of dominant groups remain highly relevant to the outcomes and that the socio-political system within which they operate is dynamic. Governance as a whole has become a playing field for dominant stakeholder groups both within and outside the government. The study demonstrates the value of CES in improving the understanding of complex governance in the context of a crisis.