An explosion at a US Steel plant in Clairton, Pennsylvania, has left two people dead and at least ten injured, officials have confirmed. The blast occurred at the Clairton Coke Works facility, which produces coke for steelmaking, sending a plume of black smoke into the sky near Pittsburgh.
Emergency services were called to the site shortly before 11 am local time on Monday. The body of one worker was recovered from the wreckage during a search-and-rescue operation, and a second fatality was later confirmed. Witnesses described the explosion as 'like thunder', shaking nearby buildings and scaffolding.
Pennsylvania Governor Josh Shapiro said his administration was in contact with local officials, offering state resources. US Senator John Fetterman, a former mayor of the nearby town of Braddock, called the incident 'absolutely tragic' and expressed solidarity with the steelworkers and their families.
The Clairton plant, which is over 120 years old, is the largest coking operation in North America. It has faced previous safety and environmental concerns, including a fire in February 2025 and a settlement in 2019 over soot emissions. The Breathe Project, an air quality group, noted this was the third major incident at the plant in 2025.
Authorities have urged residents to stay away from the area as the investigation continues. The cause of the explosion is not yet known, but the plant is part of US Steel, which recently finalised a partnership with Japan's Nippon Steel.
