establishment of the ics modular organization is the responsibility of

The establishment of the ICS (Incident Command System) modular organization is the responsibility of the Incident Commander. The Incident Commander is accountable for developing the organizational structure of the ICS based on the incident's size, complexity, and specific requirements. This responsibility includes expanding and delegating functional roles as needed while maintaining overall command and control of the incident response. The ICS organization builds modularly from the top down, with the Incident Commander initially activating only the necessary parts of the system and expanding it as the incident evolves.