Answer:
Within ICS (Incident Command System) of the United States, the Type 1 Incident requires regional or national resources, all Command and General Staff positions are activated, branches are activated, personnel may exceed 500 per operational period.
Explanation:
Type 1 Incident is the most dangerous and complicated incident for ICS to deals with. While sharing characteristics of all prior types of incidents (from 5 to 2 in ascending order of complexity), it also meets the above-stated requirements.
The involvement of national and regional resources, activation of all Command and General Staff positions, as well as branches, is necessary because an incident of this level requires a well-coordinated approach from national to the local level in order to prevent it from becoming even more disastrous. This also means large human resources involvement. In total it may even exceed 1000 operations personnel.
For example, the majority of <em>wildfires</em> are managed with local resources (Types 5 to 3), but some escalate and demand national and regional resources.
