On October 8, 2025, a significant fire broke out at ArcelorMittal’s Fos-sur-Mer plant, one of France’s largest integrated steel facilities. The fire began on two conveyor lines carrying raw materials to the steelmaking shop and quickly spread to nearby structures, according to local reports.
Internal fire brigades, supported by local emergency teams, battled the flames for several hours. While there were no reported casualties, the fire caused major damage to mechanical and electrical systems.
ArcelorMittal confirmed that the fire compromised the load-bearing structures of the conveyors and destroyed the electrical substation, leading to the immediate shutdown of blast furnace No. 2. The company stated that the furnace would remain offline for at least two days, though the closure may be extended depending on the results of a technical assessment.
The steelmaking shop is vital to the plant’s production chain, supplying slabs for downstream rolling and finishing lines. Its closure has disrupted overall production. Currently, the plant is relying on existing slab reserves, which could be depleted quickly if repairs take longer than expected.
The incident underscores the critical importance of maintaining infrastructure in integrated steel plants and the challenges of ensuring continuous production during unforeseen emergencies. ArcelorMittal is assessing the damage and preparing repair plans to resume operations while minimizing impacts on its supply chain.