Reviewed: January 2026
Introduction
The term ‘mass casualty incident’ and ‘multi-casualty incident’ (MCI) are used
interchangeably however the meaning is the same – an MCI exists when the initial
response becomes overwhelmed.
The typical definition is when the number of casualties exceeds the capacity of the initial resources, preventing effective management and conveyance.
The successful management of an MCI requires the effective use of resources to create a balance between the available supply of responders, equipment, and assets to that of the MCI.
Experience has shown that in the event of an MCI, patient care is optimized if crews
follow a pre-arranged plan, which includes the declaration of an MCI. Scene
management should include consideration of various factors including responder safety. The initial incident commander and triage officer are responsible for their tasks until relieved by senior clinicians or supervisors.
Declaring A Mass Casualty Incident
The responsibilities for the first arriving crew can be divided as follows:
The BCEHS Incident Commander provides an initial windscreen situation report and collects information necessary for the METHANE report. The incident commander is the contact between the scene and the communication centre.
Consider establishing a Unified Command with partner agencies when able.
The Triage Leader uses the START Triage or Jump Start Triage Tool to prioritize treatment and coordinate patient movement from the incident area to the Ambulance Extraction Point and reports to the Incident Commander. See Job Aid Links for specific role details.
Upon arrival of the second ambulance – following check-in with the incident commander crew will be delegated roles & responsibilities per the IC, which could include Treatment Leader OR Transport Leader OR Scribe etc.
Active Direct Threat
In the event of an Active Direct Threat – crews must refer to Active Direct Threat
Chemical, Biological, Radioactive, Nuclear and Explosive Incidents OR HAZMAT
This may also be a Hazardous Materials incident (HAZMAT) – the only difference
between a HAZMAT and a CBRNE incident is typically malicious intent.
In the event of an CBRNE – crews must refer to CBRNE
High Risk Hazards
A separate high risk hazard can be combined with an MCI – crew must refer to the
relevant HRH Guide in the BCEHS Handbook.
UNDER NO CIRCUMSTANCE ARE BCEHS PARAMEDIC AUTHORIZED TO PRACTICE IN THE DIRECT THREAT/HOT ZONE