Disaster responses are usually coordinated by a centralized authority (Incident Command System, or ICS). Teams of first-responders go out into the field, assist in recovery efforts, and collect information on injured, missing and dead, and on damage to infrastructure. These reports are conveyed to the ICS which can then determine how to deploy further resources. Part of an ICS’s function is to report casualty information to government and media.
Edit: I absent-mindedly wrote “centre” instead of “system.”
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