Although school crises are rare events, they have such devastating consequences that every school must engage in comprehensive preparedness efforts from prevention through response and recovery (Brock et al., 2016; U.S. Department of Education, 2013). These plans should be informed by research and theory and practiced until they can be implemented with high fidelity. Prevention starts before an event occurs and refers to capabilities needed to avoid, prevent, or stop a threat, thereby reducing the potentially harmful outcomes linked to the threat. Prevention plans may include multi tiered systems of support, school mental health services, and suicide and threat assessment. In this chapter, we begin with a focus on preventing school crises through the use of threat assessment as one exemplary strat egy that can be used to protect schools from violence. Although preven tion efforts are essential, schools must also prepare for a wide range of crisis events (e.g., natural disasters, accidents, violent deaths) that may occur