At Least 10 Injured, 2 Killed in Explosion at US Steel Clairton Coke Works Near Pittsburgh

At least 10 people were injured and at least two were killed on the morning of Aug. 11 in an explosion at the U.S. Steel Clairton Coke Works south of Pittsburgh, prompting a large-scale emergency response and efforts to free those still trapped under rubble, officials said.

The Allegheny County Emergency Services department said in a post on X that at least one person has been killed in the blast and that several people are still missing. Authorities later said that another person had been killed in the accident.

“Two people are currently believed to be unaccounted for, and multiple individuals have been treated for additional injuries,” the agency said. “The status of those individuals is not known at this time. Emergency Services is coordinating with all local agencies.”

One worker was pulled from the wreckage hours after the explosion sent black smoke spiraling into the midday sky in the Mon Valley, a region of the state synonymous with steel for more than a century. Authorities later said a second person had died.

Allegheny County Emergency Services said a fire at the plant started around 10:51 a.m.

A U.S. Steel spokesperson told The Epoch Times in an emailed statement that the incident involved coke batteries 13 and 14. Batteries are structures containing multiple slot type ovens used to convert coal into coke, an essential input in steel production. The spokesperson said emergency teams were dispatched to the scene immediately.

“Our top priority is the safety and wellbeing of our employees and the environment,” David Burritt, president and CEO of U.S. Steel, said in a statement provided by the spokesperson to The Epoch Times. “We are working closely with relevant authorities to investigate the cause of the incident and will provide additional updates as they become available.”

Video from a Sky 4 news helicopter shows emergency crews battling flames at the sprawling industrial site, which sits along the Monongahela River and is the largest coke-making operation in North America.

Live footage from the regional Breathe Cam appeared to capture the explosion, followed by a towering plume of dark smoke. The Breathe Project shared additional images on X, warning residents to shelter indoors.

“Prayers for those injured,” the group wrote.

South EMS Dispatch logged the incident at 11:29 a.m., labeling it a “Fire—Mass Casualty Incident,” Level 2 MCI—a designation used when local emergency resources are overwhelmed and mutual aid is required.

Pennsylvania Lt. Gov. Austin Davis said that the state was providing additional resources and urged residents to stay away from the area.

“The Mon Valley is my home, and I know people that work at the Clairton Coke Works,” he wrote on X. “Blayre and I are praying for the workers and their families, and I’ve been in contact with local leaders and the Steelworkers. The Commonwealth is providing whatever resources and manpower are needed to help with emergency response.”

Sen. John Fetterman (D-Pa.), who lives in the area and spoke to reporters at the scene of the blast earlier in the day, offered condolences.

“Without a doubt, this is tragic, what’s happened,” he said, calling the human toll “heartbreaking” and “just awful.”

In a separate statement posted on X, Fetterman urged residents to heed official guidance and avoid the site.

“My team and I are tracking this explosion and waiting for more information,” he wrote. “Keeping those injured and all who are impacted in my thoughts right now.”

The Clairton Coke Works, located along the Monongahela River about 20 miles south of Pittsburgh, is the largest coke-making operation in North America and one of four major U.S. Steel plants in Pennsylvania. The plant employs several thousand workers.

“Nearly 1,300 dedicated men and women work at the Clairton Plant each day, performing their jobs with the utmost safety,” Burritt told The Epoch Times. “During times like this, U.S. Steel employees come together to extend their love, prayers, and support to everyone affected.”

An incident at the plant in February led to a “buildup of combustible material” that ignited, causing an audible “boom,” according to the Allegheny County Health Department. Two workers received first aid at a nearby hospital after getting material in their eyes but sustained no serious harm.

The explosion comes less than two months after U.S. Steel and Nippon Steel finalized a $15 billion partnership that grants the U.S. government certain oversight powers, ending a protracted negotiation clouded by national security concerns.

The Epoch Times has reached out to U.S. Steel for comment.

Reuters and The Associated Press contributed to this report.