Fire broke out around 8:45 pm in a basement room of a building housing a pharmaceutical research centre. Black smoke emanating from the ventilation ducts of an office directly above this room alerted the watchman. The fire detection system, which went off around 9 pm, made it possible to locate the fire source. Since the facility was only active during the day, only the watchman and 2 maintenance department employees were present in the building at the time. The damaged room, known as the centre’s sample library, contained 200,000 samples of molecules and medicine precursors stemming from the firm’s research activities. Stored in flasks within a solvent medium (TMSO, tagged as noxious), the samples were: combined by plates in freezers, devoid of radioactive substances, and free of all biological or toxic risks. The combustion of plastics (flasks, plates, freezer insulation, electrical cables, etc.) caused the observed smoke emissions. Some 30 fire-fighters, including a chemical emergency squad, arrived on-site within minutes after the alarm. The fire, which remained confined in the room where it had ignited, was brought under control by the end of the evening. An electrical malfunction on a freezer motor triggered this accident. The extinction water flowed into the site’s sewer network, which could be isolated from the municipal network by an inflatable balloon placed for this purpose as in the connecting pipe. The use of foams helped limit the volume of this water to just a few m³, all of which remained on-site. The centre’s operator implemented the procedures imposed by the Prefectural order, whose response conditions had been defined in conjunction with emergency and fire protection services. The activities of employees assigned to the burnt building were stopped for an indefinite period. The value of damages could not be estimated, but the destruction of a portion, or perhaps all, of the samples stored in the library corresponded to years of research and represented a significant loss of the firm’s resources.