For the purposes of this protocol, a "critical incident" is defined as "any event or situation that threatens people and/or their homes, businesses, or community." The scope of many critical incidents, such as natural disasters, workplace violence, or domestic terrorism, requires the cooperative efforts of business and public-sector planners and responders. This presentation of the protocol encourages the public and private-sector entities that may have engaged in the assessment and planning process in isolation to form cooperative partnerships. Further, the protocol assists those businesses and communities that lack emergency planning experience in the development of a joint emergency planning process. The protocol draws on lessons learned in planning for and responding to critical incidents. It outlines lessons learned in establishing partnerships in advance, so the event can be managed and resolved with minimum loss to the community. The protocol provides guidance in conducting individual and joint public/private evaluations of risk factors and understanding what business functions are critical to individual businesses and the community. Guidance is also provided in developing joint public/private-sector emergency plans and in how community resources can be identified and shared in responding to disasters. Other issues discussed are the facilitation of business resumption and recovery, the development of training exercises, and the incorporation of mitigation throughout the entire process, while recognizing its significance in preventing a disaster and reducing its impact. Appended components of a basic information form, a tabletop exercise scenario example, 39 references (including Internet resources), and a glossary