Abstract Background Major incidents evolving from occupational accidents are very infrequent in Scandinavia and therefore, case reports are called for. On 26 November, 2024, a fatal occupational accident took place during the construction of a concrete silo in the small rural town of Flemløse (population 574), Denmark. Three people died and six were injured as the result of a collapsing concrete roof during construction. We aim to describe the incident response by the emergency medical services (EMS), to identify areas of improvement, and to evaluate the adherence to current national major incident guidelines and communication grids. Case presentation The initial call to the emergency medical dispatch center described an accident comprising fifteen injured persons, all of whom were migrant workers. Seventeen EMS units including two helicopter EMS units were dispatched to scene. Three critically injured patients were admitted to a nearby trauma center, whereas three lightly injured were taken to a regional trauma hospital. The initial reports overestimated the number of possible casualties and therefore, the available resources were ample. The very construction of the silo resulted in challenging conditions for evacuation of the injured patients. Chemical, biological, radiological, nuclear, and explosive (CBRNE) aspects of the incident added to the inherent complexity in major incident management. Although potentially detrimental to the patients, the prolonged extrication of the patients enabled the prehospital services to procure a timely organization of the incident site according to guidelines and an organized transport prioritization of the victims. The communication within EMS and between authorities was generally as per national guideline. Conclusions The EMS response to this major incident generally adhered to the national guidelines and, furthermore, the communication within and between authorities was established according to guidelines. Important findings included the use of local resources by the incident command and improvised means for the evacuation of victims from a highly hostile environment. The triage of patients adhered to local and national major incident guidelines. Migrant workers have increased risk for occupational accidents.