This chapter addresses the third step of the hazard risk assessment process, that is, hazard/event consequences. It covers the study of accident minimization/prevention and a host of others related to hazard/event consequence analysis. Event trees are diagrams that evaluate the consequences of a specific hazard. The chapter highlights the safety measures and the procedures designed to deal with the event. Consequences of accidents can be classified qualitatively by the degree of severity. On this basis, one can qualitatively rank the consequences of accidents into low, medium, and high degrees of severity. Failure modes, effects, and criticality analysis, also known as failure modes and effects analysis, is a systematic, qualitative method by which equipment and system failures, and the resulting effects of these failures, are determined. Vulnerability analysis identifies areas in the community that may be affected or exposed; individuals in the community who may be subject to injury or death from certain specific hazardous materials.