During a major propellant spill, there must be timely and reliable access to information relevant to decision-making. The completeness, utility, accuracy and rapid availability of that information will allow timely direction and implementation of actions necessary to minimize the impacts of the spill and to effectively recover property. Propellant spill accidents present a potentially serious hazard to the Air Force and the general public. Injury, environmental impact, and damage to hardware can be prevented or reduced with the use of an interactive computer system. A computerized hazard management system will provide decision-makers with rapid access to an extensive hazard response data base which can be quickly modified to reflect changing accident site conditions. The computer system will closely duplicate conditions and events at a propellant spill site and is capable of continuous hazard reaction status monitoring and performance of repetitive mathematical calculations. This paper will review the development of a hazard response computer system for use in accident mitigation, training, preplanning, and exercise evaluation. It will assist those charged with development of similar computer systems, provide guidance in tailoring the system to fulfill the needs of the user, and highlight pitfalls to avoid.