On October 5, 1994, 48 members of the Sect of the Solar Temple were found dead at two different locations in Switzerland: 23 victims in Cheiry and 25 victims in Salvan. Our Institute was commissioned to solve the forensic problems presented by this tragedy. Our goals were to establish the time of death, determine its causes, help elucidate the surrounding circumstances and identify the victims. This work presented us with the following challenges. This catastrophe was of an 'open' type: there was no list of 'passengers'; the victims were of five different nationalities and many had just arrived in Switzerland to participate in this event; family ties were very complex within this group; half of the victims were burned and sometimes charred; the exceptionally intense media converage of the story put a lot of pressure on the investigators and our Institute. In spite of these difficulties, all the victims were positively identified within 1 month. In the present report, we describe the steps realized to progress in our work. A special section describes our relationship with the journalists and their invaluable help in our investigations. The importance of being prepared for such an event is discussed