At around 3 pm, an alarm alerted the employees of an industrial joinery workshop about a lack of chippings in the boiler. When walking toward this boiler, a technician noticed smoke coming from a 200 m³ silo of chippings (one-third full). In this process, the chippings generated by the machining of wooden parts are sucked into and then stored in silos before being fed into the boiler. This boiler was stopped, the suction system and electricity were cut off and a general evacuation was initiated. Fire-fighters opened the door in the lower part of the silo in order to empty it under the protection of fire hoses. At around 5 pm, their progress was stopped by the formation of an arch, a part of which collapsed 30 minutes later; the following inrush of air then caused violent flames (including one 15 m high) which injured 6 fire-fighters. Some received burns to their hands, faces or legs, one had a fractured and dislocated shoulder and others suffered from bruising. After receiving massive reinforcements, the fire-fighters fought the fire in the silo from the top using foam. At around 6.30 pm a second flashback (2 m) injured 2 other fire-fighters. Two hours later any danger had been averted but the fire-fighters nevertheless continued to monitor the situation until 6 am. Two of the 8 injured fire-fighters remained in hospital until 20 April. The silo was damaged; electric cables and pneumatic circuits had to be replaced. Most of the production was stopped for 5 days. According to the inspection authorities for classified facilities, metal debris may have been aspirated into the suction network and could have generated sparks that caused the chippings to burn. The operator is looking into the possibility of a filtration system for such metal parts.