Why thank you dear boy; sounds a bit like OUSP just put like that so perhaps we should also paste (from same article) -
"A major incident is defined as an event or situation with a range of serious consequences which requires special arrangements to be implemented by one or more emergency responder agency. It is “beyond the scope of business-as-usual operations, and is likely to involve serious harm, damage, disruption or risk to human life or welfare, essential services, the environment or national security”. In addition, “the severity of the consequences associated with a major incident are likely to constrain or complicate the ability of responders to resource and manage the incident”."