Incident Command, Coordination, and Communication
The incident command system is a scalable, modular structure built on common terminology, unity of command, and management by objective. The first arriving responder assumes command and keeps it until formally transferred; command sets objectives and does not personally perform tactical tasks.
Structure
Command staff includes the safety officer, public information officer, and liaison officer. The general staff comprises Operations, Planning, Logistics, and Finance/Administration. Span of control is typically three to seven subordinates, with five as the target; exceeding it means adding a division, group, or branch. A unified command brings agencies with shared jurisdiction or responsibility into one set of objectives without surrendering their own authority. The planning cycle produces an incident action plan for a defined operational period.
Coordination and communication
Zones follow a hot, warm, and cold logic: exclusion, contamination reduction, and support. Communication planning should specify interoperable channels, plain language rather than codes, a common operational picture, and a designated medical channel for hospital notification and patient tracking. Public information must be consistent and released through one voice. Hospitals, EMS, public health, and law enforcement each have a role that must be requested and integrated, not assumed.
Traps
Questions test whether you know that command is not the same as operations, that unified command is not the same as a single incident commander with advisors, and that the safety officer has stop-work authority. Another common trap is assuming a federal agency takes control; local authority normally remains in charge.
Rule of thumb
One incident, one set of objectives, one voice to the public, and a span of control near five.