Triage and System Gaps Observed During a 2025 Mass-Casualty Incident in Sanxia, Taiwan: A Report from the Field

This field report describes the operational characteristics and system-level challenges observed during a real-world mass-casualty incident in Taiwan. A multisource reconstruction was conducted using post-incident debriefing records, on-scene observations, emergency medical services operational logs, and publicly available media reports, focusing exclusively on response processes without accessing patient-identifiable information. Sixteen casualties were initially identified following a vehicle-pedestrian collision near an elementary school, including 4 cases of out-of-hospital cardiac arrest. A total of 13 patients were ultimately transported to receiving hospitals. Although Simple Triage and Rapid Treatment was initiated promptly and all transports were completed within a short operational window, early triage decision-making occurred under conditions of high cognitive load and scene fragmentation. Digital support tools were available but were not activated during the initial response, necessitating reliance on handwritten notes and verbal communication for patient tracking and hospital notification. In addition, auxiliary personnel were present but not formally integrated into the incident command structure. These observations highlight execution-level challenges affecting triage coordination, information flow, and operational integration during real-world mass-casualty responses.