Informal online communication channels are being utilized for official communications in disaster contexts. Channels such as networked microblogging enable public officials to broadcast messages as well as engage in direct communication exchange with individuals. Here the authors investigate online information exchange behaviors of a set of state and federal organizations during the Deepwater Horizon 2010 oil spill disaster. Using data from the popular microblogging service, Twitter, they analyze the roles individual organizations play in the dissemination of information to the general public online, and the conversational aspects of official posts. The authors discuss characteristics and features of the following networks including actor centrality and differential mixing, as well as how structural features may affect information exchange in disasters. This research provides insight into the use of networked communications during an event of heightened public concern, describes implications of conversational features, and suggests directions for future research.