Emergency Response and Incident Command Basics
The framework
The National Incident Management System provides the structure; the Incident Command System is the on-scene management tool. Core principles are common terminology, clear text radio traffic, modular organization, management by objectives, and a manageable span of control - roughly three to seven subordinates, with five as the target. Multi-agency events of equal authority use a Unified Command rather than one agency taking over.
Roles and the first responder
The first arriving unit establishes command, announces it, and does not self-deploy into the hazard. The Incident Commander sets objectives, ensures scene safety, and delegates. The classic ICS sections are Operations (does the tactical work), Planning (collects and analyzes information, builds the action plan), Logistics (resources and support), and Finance/Administration (cost, records, reimbursement). Transfer of command requires a briefing covering situation, objectives, tactics, resources, and safety concerns.
Mass casualty incidents
Use a recognized triage system such as START, sorting by respirations, perfusion, and mental status into immediate, delayed, minor, and deceased. Treat and move; never let one patient consume the whole scene. Confirm whether the operation is rescue-task oriented or a staged, controlled evacuation, and establish staging, a casualty collection point, and personnel accountability.
Traps
Test writers like "the Incident Commander personally performs every task," "any unit may self-deploy," and "a responder should use a radio while standing next to a suspected device." None are correct. Also watch for confusion between evacuation and shelter-in-place.
Rule of thumb
Command, safety, size-up, resources, communicate - in that order, every time.