2 killed, 10 injured in Clairton Coke Works explosion

Ten others were injured, and people who live near the plant were urged to stay inside.

Timothy Quinn

Three explosions at U.S. Steel’s Clairton Coke Works shook the ground Monday, leaving two workers dead and sending 10 others to area hospitals.

A Westmoreland County man, Timothy Quinn, was one of the workers who died. A second man, who was not identified, was pulled from the rubble Monday evening after authorities spent hours combing the blast site for signs of life.

“That worker has been extricated and is now in the hands of the medical examiner’s office,” Matt Brown, Allegheny County’s chief of emergency services, said at an evening news conference.

The first explosion occurred about 10:47 a.m., according to video recorded by the Breathe Project, a clean-air group whose cameras in Clairton captured an enormous plume of black smoke billowing skyward.

That was followed by two secondary explosions, according to Allegheny County officials.

Quinn of South Huntingdon started work at 5:30 a.m. Monday, his usual shift, said his sister Trisha Quinn of Madison.

Representatives from U.S. Steel visited with the family for about 15 minutes and provided information about death benefits, she said. They had not publicly confirmed Quinn’s death.

She said her brother loved the job, following in the footsteps of their father, who worked there for 42 years. “Tim was a blue-collar guy,” she said.

A single father of three, Quinn hoped his 17-year-old son would continue the family tradition, Trisha Quinn said.

Brown said Monday evening that five of the injured remained in critical but stable condition at hospitals. Five others had been treated and released.

Two medics were also taken to an area hospital for evaluation. In total, 14 local fire departments and 20 EMS services responded to the scene.

A U.S. Steel official said at the evening press conference initial steps of the investigation will include interviews with workers and help from experts inside of the company and out.

The investigation into the explosion will involve the Allegheny County Police Department, county fire marshal, the federal Bureau of Alcohol, Tobacco, Firearms and Explosives and other agencies.

The explosions sent a shock through the community and led to officials asking residents to stay away from the scene so emergency workers could respond.

Residents of the area stated that they heard a loud noise, followed by a shockwave. William Perce of Clairton said he initially thought the explosion was from train tracks by his house.

“I came out and there was black smoke, and then all kinds of sirens,” Perce said. “My prayers go to them, and then everybody else in there.”

In a statement, U.S. Steel said an “incident” occurred at the plant’s coke oven batteries 13 and 14. The company, now a subsidiary of Japan- based Nippon Steel Corp., said emergency teams were immediately dispatched to the scene, but it gave no other details about the cause of the explosions or damage.

The company’s CEO, David Burritt, said in the statement that U.S. Steel is working with authorities to investigate the cause.

Allegheny Health Network said it treated seven patients from the explosion in its hospitals and discharged five within a few hours. University of Pittsburgh Medical Center said it was treating three patients at UPMC Mercy, the region’s only level one trauma and burn center.

The plant is considered the largest coking operation in North America and is one of four major U.S. Steel plants in Pennsylvania.

The plant converts coal to coke, a key component in the steel-making process. To make coke, coal is baked in special ovens for hours at high temperatures to remove impurities that could otherwise weaken steel. The process creates what’s known as coke gas — made up of a lethal mix of methane, carbon dioxide and carbon monoxide.

Clairton Mayor Richard Lattanzi said his heart goes out to the victims of Monday’s explosions.

“The mill is such a big part of Clairton,” he said. “It’s just a sad day for Clairton.”

Father of three killed in blast

The man killed in Monday’s explosion was identified by family members Monday afternoon after they spent hours trying to track down information from the mill and area hospitals in hopes he had been rescued.

Trisha Quinn spoke with reporters from WTAE at the scene of the explosion and said the steel mill confirmed her brother Timothy, 39, had died.

He has worked at the mill since 2008.

As the news of his passing spread, friends, family and coworkers shared memories of Timothy as they leaned on each other to grieve.

Kevin Klamorick, a coworker and local firefighter/EMT joined others in mourning the loss of his friend.

“I am truly heartbroken and speechless to hear about the passing of Timothy Quinn AKA TQ or Q,” he wrote on Facebook. “My thoughts and deepest sympathies are with your family during this profoundly difficult time. Tim wasn’t just a coworker at the Clairton Steel Mill; he was a true friend whose presence brought joy the workplace.

“I will always cherish the good times we shared, from our laughter during breaks to the countless moments spent working side by side. I fondly remember the fun we had going for a few drinks after our afternoon shifts, and how he would steal my cowboy boots, chuckling and saying, “How the hell do you wear these?” Those moments, along with our breakfast runs to Wagner’s after finishing midnight shifts, always brought a smile to my face.

“Though words seem inadequate, His memory will forever remain in my heart, and I feel thankful to have shared part of my life with such a remarkable person.”

Leaders react

On X, formerly known as Twitter, Gov. Josh Shapiro confirmed Monday that multiple explosions occurred at the U.S. Steel plant. He added that he had been in constant contact with labor leaders and County Executive Sara Innamorato.

“Injured employees have now been transported to local hospitals to receive care, and search-and-rescue efforts remain active at the plant,” Shapiro wrote. “If you’re in the area, continue to follow the instructions of local authorities.

“Lori and I are eternally thankful for the bravery of our first responders — and we continue to pray for the entire Clairton community.”

The Allegheny County Health Department and Innamorato said the county was monitoring the explosions and advised residents within 1 mile of the plant to remain indoors, close all windows and doors, set air conditioning systems to recirculate and avoid drawing in outside air, such as using exhaust fans.

That request was lifted around 7:30 p.m.

Lt. Gov. Austin Davis, a McKeesport native, reiterated what Innamorato asked and recommended local residents follow officials’ guidance.

“As we continue to receive updates about the explosions at the U.S. Steel Clairton Coke Works facility in Allegheny County, please continue to follow all directions from officials, including the recommendation of residents to remain indoors, and limit your exposure outside for those within a one-mile radius of the plant,” Davis wrote on X.

State Sen. Nick Pisciottano, D-West Mifflin, who represents Clairton in Senate District 45, said he’s been in contact with Shapiro and other officials.

“My thoughts are with the workers, their families, and all members of our community impacted by today’s explosion at the U.S. Steel Clairton Coke Works,” Pisciottano said. “I am grateful to the first responders and medical professionals who acted swiftly to provide care and secure the scene.

“Earlier today, I was on site at the mill and at the United Steelworkers union hall meeting with workers monitoring the situation. Developments are still unfolding, and I have been in touch with Governor Shapiro’s office, Lieutenant Governor Davis, County Executive Innamorato, Mayor Lattanzi, and local officials and emergency responders to ensure a coordinated response.”

U.S. Sen. John Fetterman, D-Braddock, said he was in the area when he heard about the explosion and decided to drive by.

“My whole thoughts goes to the families, and they’ve lost someone today, and it’s just absolutely tragic,” Fetterman said. “I grieve for these families, and again, I’m proud to stand with the steel workers and to make sure that we do everything possible after this terrible tragedy.”

Other local officials reacted to the incident, including Senate President Pro Tempore Kim Ward, R-Hempfield Township.

“For generations, U.S. Steel and the Clairton Coke Works plant have stood as symbols of Western Pennsylvania’s work ethic and determination,” Ward said. “Our region’s story has been forged in the heat of steel mills by people who do not back down from challenges but instead stand shoulder-to-shoulder in hard times. In the face of heartbreak, we will not waver — because in Western Pennsylvania, we are forged in steel and we do not break.”

Monitoring air quality

Officials from the county health department said air monitors have not detected emissions of certain compounds above federal standards.

A representative for the U.S. Occupational Safety and Health Administration, which monitors workplace safety, confirmed the agency was aware of the incident and is “looking further” into it.

At the scene, at least a dozen marked emergency vehicles were near the State Street plant around 12:30 p.m.

First responders in yellow vests clustered around a gate leading to the 392-acre property along the Monongahela River.

A group of women gathered around noon at a Speedway gas station at the corner of State Street and Maple Avenue. They quickly called those they knew inside the plant after the explosion.

Dave Evans, a Monessen volunteer firefighter, arrived at the coke works around 1:50 pm with pallets of water and Gatorade — 2,500 bottles of water alone.

“There’s a lot of guys back there,” said Evans, 53, of Monessen. “This is for the first responders, for anybody.”

The Clairton Coke Works is one of four facilities that make up U.S. Steel’s Mon Valley Works, along with the Edgar Thomson Plant, Irvin Plant and Fairless Plant.

The Clairton plant is the largest coke manufacturing facility in the nation, according to U.S. Steel. It operates 10 coke oven batteries and produces about 4.3 million tons of coke each year.

As the only remaining U.S. Steel coke-producing plant in the country, the Clairton facility employed about 1,400 people as of 2023, according to a U.S. Steel report. St. Clair Steel Company built the facility in 1901. U.S. Steel purchased it in 1904.

Environmental organizations such as PennEnvironment spoke out after the incident, citing previous lawsuits against U.S. Steel and the poor conditions of its facilities.

“First and foremost, PennEnvironment is sending out our thoughts and prayers to the individuals caught in this catastrophic accident and their families, as well as the local community members in and around Clairton, Pa.,” said David Masur, the organization’s executive director.

“PennEnvironment and the Clean Air Council sued U.S. Steel back in 2019 alleging that the crumbling, poorly maintained, highly polluting Clairton plant posed a health threat to communities across the Mon Valley, as well as to its own workers,” Masur said. “We need a full, independent investigation into the causes of this latest catastrophe and a reevaluation as to whether the Clairton plant is fit to keep operating.”

The Breathe Project, a Pittsburgh- based environmental non-profit, stated that Monday’s incident was the third major event at the Clairton plant in 2025. They stated there was a stack explosion Feb. 2, and a pollution control room malfunction June 2-3.

Breathe Project added that local organizations and residents have been concerned about the facility for a long time. They added that U.S. Steel has paid nearly $64 million in air pollution enforcement actions, fines and settlements related to the Mon Valley Works’ three facilities since January of 2020.

Long history of pollution concerns

In recent years, the Clairton plant has been dogged by concerns about pollution. In 2019, it agreed to settle a 2017 lawsuit for $8.5 million. Under the settlement, the company agreed to spend $6.5 million to reduce soot emissions and noxious odors from the Clairton coke-making facility.

The company also faced other lawsuits over pollution from the Clairton facility, including ones accusing the company of violating clean air laws after a 2018 fire damaged the facility’s sulfur pollution controls.

Community aids first responders

Many neighbors and dozens of first responders worked in the heat under extremely difficult conditions following the tragedy, and donations were collected to help support them.

SouthEast Regional EMS and multiple partner agencies were overwhelmed with community donations of bottled water, sports drinks snacks and other cooking supplies.

By Monday evening, the EMS service said it had received more than enough supplies to help.

“Our community showed up BIG,” SWREMS stated in a social media post. “The generosity of this community has been nothing short of incredible. In just a short time, you came together and provided everything we needed — and more. Your donations, kind words, and support remind us why we are proud to serve here.”

Items not used during Mondays response will be donated and put to good use.

“At this time, we have received ample supplies for today’s incident. Any items not used will be shared with our local partner agencies and the Salvation Army to ensure they’re ready for the next time help is needed,” SWREMS added. “The Salvation Army continues to accept donations year-round for their rehab units, your contributions will always find their way to someone in need.

“From all of us — thank you for standing with us, for lifting up your responders, and for showing what a strong, compassionate community can do.”

The Associated Press and TribLive contributed to this story.