The article presents an approach to emergency response training that combines simulation of hazardous environmental factors with extensive registration of the activities in a training scenario. Simulation enhances realism by exposing the trainees to representations of hazards without putting them at risk. Registration generates data that describe the course of events in the exercise. These data form a mission history, which is a time-synchronized, event-based model of the exercise that can be replayed and reviewed in the MIND presentation tool to support debriefing in an after-action review. We illustrate our approach by discussing important training sequences and key events in two live emergency response exercises in Sweden and in the United States. (Contains 3 figures and 1 table.)