Objective: The purpose of this study was to examine interorganizational collaboration in suicide prevention activities coordinated by the fire service. Method: Interviews and observations were conducted in ethnographic fieldwork in three Swedish fire stations. The analysis of data was guided by interagency collaboration theory. Results: The findings demonstrated six central components of the practice: (a) a shared suicide incident plan for the emergency services, (b) a municipality action plan supported by the Swedish Law of protection against accidents viewing suicide as a psychological accident, (c) interagency groups working with suicide prevention, (d) education and training of firefighters and the public in Mental Health First Aid and suicide prevention, (e) suicide intervention operations carried out by the emergency services, and (f) crisis support of bereaved families and first responders exposed to suicide. Conclusions: Having a shared suicide intervention plan and practice created trust in interagency groups facilitating cooperation in suicide emergencies. The benefit of the fire service coordinating the suicide prevention activities was that the fire stations were many and geographically dispersed, unlike the police and ambulance. This meant that the fire service arrived at suicide attempt sites faster than ambulance and police, which saved lives. The results provide a starting point for the implementation of suicide prevention activities, training of firefighters, and the design of interorganizational collaboration in suicide intervention policy elsewhere in the world while adapting to regional and local circumstances and resource availability. These results might be considered in future strategy and the prioritization of suicide prevention activity.