A decision support system and method of assessing an intervention action in response to a hazard situation. The decision support system outputs information representing the hazard situation by combining data from data sources describing one of the hazard situation and a physical domain including at least one source of real-time data from the physical domain. A simulation is run using rules to predict the behavior of individual agents in response to the hazard situation, where the system selects one action from a set of candidate intervention actions based on the behavior predicted by the agent and tests the selected intervention action by initiating, for each of a predetermined set of possible outcomes of the selected intervention action, an operation to reiterate the simulation with a respective possible outcome as a factor influencing agent behavior.