An explosion struck Nippon Steel's plant in Muroran, Hokkaido, around 1:10 a.m. on Monday, shaking nearby homes. The blast occurred on a hot stove supplying air to the blast furnace, with no injuries reported and the fire controlled after about seven hours.
The incident unfolded at approximately 1:10 a.m. on December 1, 2025, at Nippon Steel Corp.'s Muroran plant in Hokkaido. A resident nearby alerted emergency services, stating, “It felt like our house was shaking. It seems like a fire broke out inside the facility.”
The Muroran fire department confirmed the explosion originated from a hot stove, which provides high-temperature air to the on-site blast furnace, leading to a subsequent blaze. Firefighters contained the flames roughly seven hours later, around 8 a.m., with no injuries among workers or residents.
The affected blast furnace has been shut down, and officials report no danger of hazardous material leaks. The Hokkaido Prefectural Police and other authorities are probing the cause. As a key facility for Nippon Steel's iron production, the plant's operations may face temporary disruptions, though the company has not detailed impacts yet. Such events highlight potential maintenance challenges in heavy industry, pending further investigation results.