Abstract: Emergency planning is an ongoing activity in which a multidisciplinary group of experts intermittently collaborate to define the most appropriate response to risks. One of the most important tasks of emergency planning is risk reduction. Such a task compiles the analysis of capabilities to face an emergency, the prioritizing of activities, and the definition of procedures and strategies. It is therefore a reflection process based on exchanging information between planners and exploring alternatives. Despite the exploration of alternatives is an especially relevant activity to design better plans, recent research on computer-mediated collaborative tools for planning do not usually offer support for this activity. Thus, with the purpose of supporting reflection during the development of risk reduction tasks, this paper presents an exploratory design tool that allow planners to assess the space of alternatives and the underlying information related those alternatives. This planning tool will help planners to examine and contextualize information, allowing them to define more suitable response strategies.