Adversities are mostly investigated and debated according to their negative impacts and to the emergency action they demand. This article presents the results of research on the paradoxical potentialities (positive externalities) that might emerge from them. Its main approach is provided by interviews with local agents responding to the 2011 Disaster in the State of Rio de Janeiro and by international aid agencies. The main topics discussed here are: solidarity as an asset that goes beyond altruism, the distinguished role of the media and the state as regulator agents of such solidarity, and the increasing importance of international aid agencies. This empirical study is based on a series of interviews with selected international aid agencies according to their global activity and volume of resources administered. The conclusions indicate that potentialities may be recognized as real assets in post-disaster action; however, they are not easily understood by policymakers.