You likely have Business Continuity plans in place to deal with various scenarios such as mass transit incidents, data centre outages, building incidents and maybe even epidemics which impact a percentage of staff. Have you considered plans for a pandemic which has the potential for all employees in a location or perhaps country needing to be isolated from congregating and forced to work remotely?
Traditional plans typically address a disaster affecting one location and often plan for only critical employees being enabled to work. This may include them working from a different office, leveraging colocation facilities or working from home. These approaches work for isolated incidents and are often based on relatively short-term scenarios targeted at fewer individuals. In the event of a pandemic everything changes.