An explosion occurred around 5 pm inside the production workshop operated by a pyrotechnician. Fire spread to the charger workshop, which was adjacent to the production shop, as a consequence of changes introduced by the manufacturer following expropriation of a portion of the facility. The fire also spread to the composition workshop, located 7 m from the workshop where the explosion first erupted. However, 65 kg of powder, along with the entire inventory of fireworks, the fireworks colour room and other lightweight buildings were all spared. Fire-fighters counted 23 dead and 12 seriously injured, all of whom were transported to the nearest hospice facility. The press announced a total of 40 victims. The Public Health & Hygiene Council made a site inspection. The suddenness of the explosion, coupled with the fact that the most heavily damaged wall was the one with the lightning rod attached, suggested that lightning may have been at the origin of this catastrophe. The pyrotechnician moved his set-up to Prés Saint-Gervais and introduced prevention measures, namely: safety distance between the fireworks depot and the charger workshop and then between the charger workshop and the colour warehouse; separation of production facilities from storage areas; buildings designed for rapid evacuation; heating by the circulation of hot water; lighting by lamps with reflectors positioned outside the workshops; and protection of window surfaces (using blinds) in order to avoid materials heating up and prevent malicious intent.