As the military saying goes, "Prior planning prevents poor performance." This phrase can be applied to preparing for mass-casualty incidents (MCIs). The FireRescue1 MCI resource page details best practices for significant incidents, including active shooter and terrorist events, transportation incidents like bus crashes or train derailments, and other incidents that could involve many victims. Read news about MCIs, like the boat fire that killed 34 and the light rail train derailment in California, plus lessons learned from MCIs, like the Beirut explosion and the Las Vegas shooting. Stay prepared to response to these high-risk/low-frequency incidents.