During the night from 18th to 19th of December 2004, at the Pyreneans Hospital Centre at PAU (France), Chantal Klimaszewski et Lucette Gariod, a nurse and her auxiliary, two of us, have been killed wildly and found by morning team. CUMP’s members (Medico-Psychological Urgency Cell) but also colleagues of the two victims, we were called at the very beginning to intervene. The question was, in accordance with of the CUMP’s missions, to help our fellow workers, families, and all participants with a psychological care, and we were also shocked by the tragedy. Over and above this the killer was a hospital patient (that’s what the investigation had discovered) We’ll try a narrative of our action by one of the department’s members after some information’s about CUMPS’s origin’s and mission’s nature. This narrative is a debriefing; a real debriefing; limited in the theory because feelings and emotional experiences are showing though facts. Probably we are not objective enough about this experience, neither about our instantaneous action to propose you a deeply analysis. So we propose you some interrogations and our point of view, about the pertinence to intervene and the way that we answered at the request urgency action.