Deadly explosion at US Steel mill outside Pittsburgh raises safety concerns

Nippon Steel's acquisition of US Steel puts focus on maintenance and environmental compliance at Clairton Coke Works

Published on Feb. 12, 2026

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A deadly explosion at the Clairton Coke Works outside Pittsburgh in August 2025 killed two US Steel workers and injured 11 others. The blast highlighted ongoing safety and environmental issues at the aging facility, which has a history of accidents and clashes with regulators over air pollution. As Nippon Steel takes over US Steel, questions remain about whether the new owner will invest significantly to address these problems at the Clairton plant.

Why it matters

The Clairton Coke Works is a massive and complex facility that has long been a source of air pollution and safety concerns in the Pittsburgh region. The August 2025 explosion, which occurred during a maintenance procedure, raised new questions about US Steel's commitment to worker safety and environmental compliance at the plant. Nippon Steel's acquisition of US Steel puts the spotlight on whether the new owner will prioritize addressing these longstanding issues.

The details

The August 2025 explosion happened while workers were preparing to replace a damaged valve at the Clairton Coke Works. According to the Chemical Safety Board, US Steel's written procedure did not mention the use of high-pressure water, which a supervisor directed the workers to use. This caused the valve to crack, releasing coke oven gas that then ignited. The blast killed two US Steel workers and injured 11 others. The Clairton plant has a history of accidents, with three fatal incidents since 2009. Some current and former workers blame US Steel's management and underinvestment in maintenance for causing operational problems and safety issues at the aging facility.

  • On August 11, 2025, the deadly explosion occurred at the Clairton Coke Works.
  • In February 2025, a problem at a battery led to a 'buildup of combustible material' that ignited, injuring two people.
  • In 2014, a worker was burned and died after falling into a trench at the Clairton plant.
  • In 2010, an explosion injured 14 employees and six contractors at the Clairton facility.
  • In 2009, a maintenance worker was killed in a blast at the Clairton Coke Works.

The players

Don Furko

A 25-year steelworker and former Clairton local union president who rushed to the scene of the August 2025 explosion.

Renee Hough

A utility technician in charge of loading coke at the Clairton Coke Works, who was in the cab of the plant's screening station when the explosion occurred.

US Steel

The owner of the Clairton Coke Works, which has faced a long history of accidents, environmental violations, and clashes with regulators over air pollution at the facility.

Nippon Steel

The Japanese steel company that acquired US Steel in a $15 billion deal in June 2025, raising questions about its plans for the Clairton Coke Works.

Chemical Safety Board

The federal agency investigating the August 2025 explosion at the Clairton Coke Works.

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What they’re saying

“I can't even explain how mangled everything was. There were flames everywhere.”

— Don Furko, Steelworker (Pittsburgh's Public Source and The Associated Press)

“My first thought was I was dead.”

— Renee Hough, Utility technician (Pittsburgh's Public Source and The Associated Press)

“They try to say 'safety first, safety first.' Safety is not the first priority for them.”

— Brian Pavlack, Current Clairton Coke Works worker (Pittsburgh's Public Source and The Associated Press)

What’s next

The Chemical Safety Board has recommended that US Steel conduct a siting evaluation of all buildings at the Clairton plant that are occupied or could be occupied to identify and assess potential hazards for workers. It remains to be seen how Nippon Steel and US Steel will address the board's findings as the new owner takes over the facility.

The takeaway

The deadly explosion at the Clairton Coke Works highlights longstanding safety and environmental issues at the aging facility, which has a history of accidents and clashes with regulators. As Nippon Steel takes over US Steel, the new owner faces pressure to significantly invest in upgrading the plant, improving worker safety, and reducing its air pollution footprint in the Pittsburgh region.