Around 9:50 am, a violent fire followed by heavy explosions broke out inside a fireworks depot. The fire generated a thick smoke cloud. The storage building roof collapsed, and ignited projectiles were responsible for spreading the fire to a lorry strongbox, placed on the ground and used to store pyrotechnic substances, as well as to an adjacent building containing packaging materials and accessories (domino effect). Crews of roughly 20 fire-fighters relayed one another in battling the blaze, which was eventually controlled around 5 pm. Some crew members remained onsite throughout the night in order to monitor for any resumption of fire. A 200-m safety perimeter was established, encompassing departmental highway D212. With approval from explosives disposal authorities, this D212 road was reopened to traffic. The site was secured by the gendarmerie and regular patrols were scheduled. The initial investigation findings pointed to an employee failing to comply with the safety rules applicable to pyrotechnic activities. This employee was performing electrical arc welding inside the storage building when the fire erupted in back of where he was working and then spread. The projection of incandescent debris was the likely source of this incident. The employee was burned on the face and hands, and a fire-fighter sustained a slight hand injury. The storage premises and strongbox were destroyed, and the neighbouring building damaged.

On the day of the accident, the company did not hold any of the required permits or certifications to operate a fireworks storage facility. The quantity of stored explosives could not be identified, as all computer records were destroyed in the fire. Invoices submitted by the company nonetheless suggested that the 2-tonne capacity of active materials had been reached and even exceeded. The classified facilities inspectorate issued a report of its findings.