A series of explosions rocked U.S. Steel's Clairton Coke Works near Pittsburgh, Pennsylvania, at 10:51 am on 11/8, sending plumes of smoke into the air and shaking the surrounding area, according to Allegheny County Emergency Services.

"It sounded like a clap of thunder," said Zachary Buday, who works nearby. "The catwalk vibrated, my chest shook, and the whole building rumbled. We saw the smoke, but no flames."

County officials dispatched 20 emergency medical services (EMS) units and personnel from 14 local fire departments to the plant for fire suppression, search, rescue, and recovery efforts.

In a press conference later that day, Allegheny County officials confirmed two fatalities and at least 10 injuries. The injured were being treated at local hospitals.

The fire at the plant was brought under control. The Clairton Coke Works, which employs about 1,300 people, is located along the Monongahela River, about 32 km south of Pittsburgh. It is the largest coke-producing facility in North America, operating 10 coke oven batteries and producing about 4.3 million tons of coke annually.

Authorities are investigating the cause of the explosion. The coke-making process typically produces coke oven gas, a mixture of methane, CO2, and CO.

The Clairton plant has faced pollution concerns in recent years. In 2019, the plant settled a 2017 lawsuit for USD 8.5 million, with U.S. Steel agreeing to spend USD 6.5 million to reduce emissions and noxious odors emanating from the facility.

U.S. Steel also faces other lawsuits related to pollution at the plant, including allegations of violating the Clean Air Act following a late 2018 fire that damaged the sulfur dioxide control system.

A view of the Clairton Coke Works in Pennsylvania on 11/8. *Photo: AP*

Duc Trung (According to WLWT, AP, Washington Post)