Authorities are working to uncover the cause of a deadly explosion at a U.S. Steel plant outside Pittsburgh that killed two people and injured 10 others Monday morning, leaving charred debris and heavy plumes of smoke in its wake.
Allegheny County Emergency Services reported that the blast occurred inside a battery operating area around 10:51 a.m. Officials have not yet provided details on the extent of the damage or a definitive cause.
Scott Buckiso, chief manufacturing officer for U.S. Steel, told reporters that the company is still working to understand what happened and is cooperating fully with investigators. U.S. Steel, now owned by Japan-based Nippon Steel Corp., is partnering with authorities during the probe.
Company CEO David B. Burritt emphasized the firm’s longstanding commitment to safety, saying he ends every meeting with the reminder to “get back to work safely,” a principle he noted “has never been more important” in the wake of the tragedy.
Emergency crews said five of the injured remain in critical but stable condition, while another five were treated at hospitals and released. Several others were treated on-site, though an exact count was unavailable due to the scale of the incident.
The Clairton plant, located along the Monongahela River, employs about 1,400 workers and is the largest coking operation in North America. The site processes coal into coke, a vital material in steel production, by baking it at extremely high temperatures for hours to remove impurities. The process also generates coke gas, a hazardous mix of methane, carbon dioxide, and carbon monoxide.
David Masur, executive director of the environmental advocacy group PennEnvironment, which has previously sued U.S. Steel over pollution concerns, called for “a full, independent investigation into the causes of this latest catastrophe” and questioned whether the facility should continue to operate.
The investigation is ongoing, and officials have not provided a timeline for when their findings might be released.
