At 12:30 a.m., the breach of a 40 tonne furnace resulted in five tonnes of molten material (three tonnes of slag and two tonnes of metal) being spilt at an upper-tier Seveso iron and steel plant. The plant’s firefighters brought the fire under control before the arrival of the public firefighters. They finished at around at 3:30 a.m. The facilities were repaired until 6:30 p.m. The materials remaining inside the furnace were poured out after three tonnes of turnings were added and melted for two hours in manual mode. The refractory material was repaired in full over the following weekend, i.e. three weeks before the initially scheduled date. The plant’s internal emergency plan was not implemented. According to the operator, the wear of the refractory material had been reported when the furnace was being prepared the day before. However, the spraying of fresh refractory had been postponed until after the pouring of the first casting because the spray machine was not working (air valve of the solenoid valves closed). The premature wear was due to an error in the assembly of the refractory material during the previous full repair seven weeks earlier and which had led to a modification in the electrical settings of the melting parameters.