An explosion followed by a fire occurred at 11 a.m while a subcontractor was performing an intervention on an oil extractor that had been shut down. The accident happened in the canola seed extraction (with hexane) building at a plant specialised in the manufacture of cooking oil. A thick column of black smoke was visible in the city. The explosion was heard from several hundred metres away. The internal contingency plan was initiated at 11:20 a.m. The facility operator stopped the supply of hexane into the building at around 11:30 a.m. The supply line was connected to a 60 m³ underground tank containing just 43 m³. When the emergency services arrived, the five-storey building was on fire. The firemen set up a 300 m safety perimeter and evacuated 7 homes in the area. The nearby road was closed to traffic, and electrical power was cut off around the site until 5 p.m. The fire brigade was able to bring the fire under control by spraying foam after 3 hours of intervention. The remaining fires were put out with water. The extractor was cooled down with 4 hoses, but the fires inside it remained inaccessible. The fire brigade let the remaining residues burn under control. The tanks of flammable liquid located in the building (hexane and effluents) were not damaged. A security guard was posted at the site over the weekend. The fire was declared as extinguished the following day at around 5 p.m. The two maintenance technicians working on the extractor were killed, two other subcontractors suffered from shock, and seven employees were injured or in a state of shock. The extinguishing water retained in the company’s networks and basements was pumped out by a specialised company (180 m³) while the extractor was cleaned out by a fire hose to remove the canola. All stocks of raw materials and finished products (6,229 t of canola, 800 t of oil and 180 t of bulk cake) were removed. The building suffered extensive damage: roof blown off, windows blow out, the building structure was damaged in places (concrete crumbling under the effect of the heat). More than 80% of the extraction equipment was destroyed by the blast overpressure or the fire. No damage was noted to the buildings and installations adjacent to the building where the explosion occurred. Flakes had become jammed in the extractor on the day before the explosion. The extractor had been shut down so that a subcontractor could remove the blockage. At the time of the explosion, one of the subcontractors was inside the extractor and wearing breathing apparatus owing to the presence of residual hexane vapours. The operation involved vacuuming out the material using a hose connected to a high-pressure flushing truck. The Inspection authorities for classified facilities proposed that emergency measures be taken to ensure the emptying of the building’s hexane circuit and the flammable liquid tanks, inspection of the gas pipelines, monitoring of the silos for the actual self-heating risk and elimination of the fire extinguishing water (300 m³). During their visit on 26/04, the Inspection authorities for classified facilities noted that the hexane circuit had been drained to the underground tank. Pumping operations are foreseen to drain the tank through the manhole. Subsequent verification of the gas pipeline network by a specialised organisation allowed the boiler to be restarted. The Inspection authorities consider that the remaining residues present constitute a risk of overheating. However, there is little combustible material, and a permanent presence is ensured, with daily rounds being performed.