Dozens of people were injured and trapped under rubble after a huge explosion at a Pennsylvania steel coking plant on Monday morning, per officials.

Emergency crews rushed to the US Steel Clairton Coke Works plant after locals heard a loud boom in the Pittsburgh-area plant.

Allegheny County representatives informed WTAE about an ongoing rescue operation for individuals trapped beneath the debris at the plant. The exact number of people still caught remains unknown as of 1pm EST.

The Allegheny County Emergency Services reported that a fire ignited at the plant around 10:51am EST, with five individuals sent to hospitals. The agency withheld further details on the transported individuals, only noting that it is an ‘active scene.’

Footage from the scene shows firefighters battling flames at the plant as ambulances go in and out of the area. 

The number and extent of injuries remains unclear but multiple medical helicopters were seen on their way to the plant.

Officials declared a mass casualty incident to allow for additional EMS resources to respond. 

Abigail Gardner, director of communications for Allegheny County, said they are not aware of any confirmed casualties. 

Dozens of people were injured and trapped after an explosion at the US Clairton Coke Works plant near Pittsburgh

Allegheny County officials said there is a rescue mission underway for people trapped under rubble in the plan

First responders rushed to the scene on Monday morning after locals heard a loud boom

Kasey Reigner, spokesperson for Allegheny County’s emergency services, remarked, “We’ve had numerous walk-ins and injured. Some have been transported. I’m still gathering complete details.”

Clairton Mayor Rich Lattanzi conveyed on X, “There was an explosion reported! Requesting numerous ambulances! My thoughts are with everyone involved in this tragedy, including their families and the community.”

He later shared on Facebook, “It was a dreadful incident, and our thoughts go out to all the families affected. There are injuries, and addressing them is our top priority.”

The Mayor assured that the ‘issue along with the affected equipment and gas is under control and not impacting the Clairton Community or neighboring areas.’

Senator John Fetterman, who rushed to the scene, asked people to stay away from the area.

‘For those in the area, please listen to local officials and avoid the area,’ he said on X. ‘Keeping those injured and all who are impacted in my thoughts right now.’

Local Melanie Dawn wrote on Facebook: ‘This explosion made our houses shake. I thought my son had hit his gas tank on the dirt bike. 

‘My niece felt it on Chambers Street, I felt it on Shaw Avenue. My teenage son’s ears were ringing.’ 

US Steel has not yet issued a statement.

Firefighters were on the scene battling the flames after the explosion on Monday

Multiple ambulances were seen coming into the plant following the explosion

Governor Josh Shapiro said on X his administration was in touch with local officials dealing with the aftermath of the explosion.

‘The scene is still active, and folks nearby should follow the direction of local authorities. Please join Lori and me in praying for the Clairton community,’ he said.

The plant, a massive industrial facility along the Monongahela River south of Pittsburgh, is considered the largest coking operation in North America and is one of four major US Steel plants in Pennsylvania that employ several thousand workers.

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, on the Monongahela River about 20 miles  south of Pittsburgh.

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