[en] This study presents an exercise of a major train accident organised in SE Finland in the spring of 2002. A specific method was used to collect and share experiences among the participants. This method, originally developed for the analysis of real accidents and crisis, demonstrates a strong potential to improve the overall benefits of this kind of exercise. The special feature of this exercise was the cooperation between different authorities and voluntary groups. The authorities represented rescue services, police, healthcare, mental crisis care and social care. The voluntary groups included both first aid and mental crisis care groups. The success of an exercise depends on two main factors : motivation of people and similarity with real conditions. The challenge in learning lessons from an exercise is to collect and share efficiently facts, decisions and individual perceptions in order to reach two objectives : evaluation of the exercise by itself and evaluation of successes and failures of technology, people and organisation that would have a significant effect in real situations.