Aug. 11 (UPI) — One worker died, one person is missing and 10 were injured after an explosion at the U.S. Steel Clairton Coke Works’ two baked oven batteries near Pittsburgh, officials said.
Nearly 1,300 employees work at the plant about 15 miles southeast of Pittsburgh, which is known as Steel City.
The explosion, which occurred before 11 a.m. EDT, could be felt miles away. The Allegheny County Health Department advised people who live within a mile to stay inside and close the windows, though air-quality levels were not detected above federal standards.
Five victims taken to Allegheny Health Network’s Jefferson Hospital were discharged, WTAE-TV reported. One person went to the network’s Level 1 trauma center, Allegheny General Hospital, and another to Forbes Hospital. The University of Pittsburgh Medical Center said three patients were taken to Mercy Hospital.
Also, two medics were taken to the hospital for evaluation.
One person was pronounced dead at a hospital.
Victor Joseph, the assistant superintendent for Allegheny County Police, said during a news conference that one missing person was found and taken to a hospital.
But one worker is unaccounted for. Personnel are actively searching for that worker and they have a general idea of the location, Scott Buckiso, executive vice president and chief manufacturing officer for U.S. Steel, said at the briefing.
He said the plant is stable and the cause of the explosion is unclear.
“It’s very preliminary,” Buckiso said. “We don’t have any details right now.”
Before the news conference, U.S. Steel explained it involved coke batteries 13 and 14. They were shut down. KDKA-TV reported the batteries are in a room that serves as a mechanical regulator to make sure coal bakes evenly in the oven.
“Our top priority is the safety and well-being of our employees and the environment,” David B. Burritt, president and Chief Executive Officer of U.S. Steel wrote in a post on Facebook. “We are working closely with relevant authorities to investigate the cause of the incident and will provide additional updates as they become available. … During times like this, U. S. Steel employees come together to extend their love, prayers, and support to everyone affected.”
Gov. Josh Shapiro posted on X that “multiple explosions” occurred at the plant. “Injured employees have now been transported to local hospitals to receive care, and search-and-rescue efforts remain active at the plant.”
Officials later said there was one explosion.
At 10:50 a.m. EDT, emergency medical services received a call for an “ongoing situation” at the plant for a potential mass casualty event, Reigner told the Post-Gazette.
A Level 3 Mass Casualty incident was declared and more resources across the region were deployed. That includes the Bureau of Alcohol, Tobacco, Firearms and Explosives Pittsburgh Field Office.
Matthew Brown, chief of Allegheny County EMS, said 20 EMS agencies and 14 local fire departments were called to the scene.
WTAE-TV’s helicopter shows video of fire crews battling flames while ambulances rushed to the area.
“Felt like thunder,” Zachary Buday, who was working close to the scene, told WTAE. “Shook the scaffold, shook my chest, then shook the building. Then we saw the smoke coming up from the steel mill.”
He said there wasn’t fire but black smoke.
Deanna Forkey, who works at a deli near the plant, told CNN the explosion caused the business’ doors to fly open.
The United Steelworkers Union confirmed several workers were injured.
“While we are still determining the scope of the tragedy, we are aware that multiple workers are receiving medical treatment for their injuries,” USW District 10 Director Bernie Hall said in a statement to CNN. “In the coming days, we will work with the appropriate authorities to ensure a thorough investigation and to see that our members get the support they need.”
Lt. Gov. Austin Davis, who grew up near the area in McKeesport, posted on X: “The Commonwealth is providing whatever resources and manpower are needed to help with emergency response. Please stay away from the area at this time to allow emergency crews to do their job and follow all future guidance from officials for those that live nearby.”
“The mill is such a big part of Clairton,” Clairton Mayor Richard Lattanzi told KDKA. “For anyone that works, how old or young you are, you have to work every day, you need to go home healthy, and some people are not going to see the same husband or son or somebody that’s working the mill. It’s just a sad day for Clairton.”
Sen. John Fetterman, who serves Pennsylvanians and appeared at the news conference, wrote on X: “My team and I are tracking this explosion and waiting for more information.”
Clairton Coke Works, which is 392 acres situated along the Monongahela River, is considered the largest coke manufacturing plant in North America with several million tons produced annually.
In the process, raw coal is turned into coke, which is used in steelmaking.
The company’s headquarters are in Pittsburgh.
U.S. Steel, which was founded in 1901, has about 22,000 employees with revenue of $15.6 billion in 2024.
In May, President Donald Trump announced a partnership with Japan’s Nippon Steel Corporation. He also said there would be a 50% tariff on imported steel. He appeared at the Edgar Thomas Plant near Braddock.
Pennsylvania has the most injury reports at still mills, according to the Occupational Safety and Health Administration.
Nationwide over 10 years, there were 266 severe injuries in still mills, including 194 that required hospitalizations and 98 in amputations, according to OSHA.
The Clairton plant settled a 2017 suit for $8.5 million about pollution, including spending $6.5 million to reduce soot emissions and noxious odors, CNN reported.
