The 11 March 2011 Tohoku-oki, Japan, earthquake, tsunami, and nuclear reactor disasters shattered existing plans for decision making, preparedness, and response operations under conditions of uncertainty and risk. The interaction among these events created dynamics that could not be addressed by any single organization or jurisdiction alone and that had not been considered in the planning processes undertaken by separate jurisdictions and organizations. The scale and scope of devastation overwhelmed those responsible for protecting communities at every level of jurisdictional decision making and organizational management. We examine the policy problem of decision making involving interaction between human and natural systems, and review existing policies, plans, and practices that characterized efforts in disaster risk reduction in Japan prior to 11 March 2011. We contrast these plans with observed practices, focusing on interactions and communication flows among organizations engaged in responding to the disaster. These events demonstrate the compelling need to rethink catastrophe.