Aug. 16 (UPI) — The deadly explosion in the Steel Clairton Coke Works near Pittsburgh occurred when a gas valve was flushed in preparation of planned maintenance, U.S. Steel said in preliminary findings.
Two people died and 10 people were hospitalized on Monday in the explosion at the plant about 15 miles southeast of Pittsburgh. Black smoke could be seen for miles.
“Pressure built inside the valve, leading to valve failure and coke oven gas filling the area and ultimately exploding when finding an ignition source,” U.S. Steel spokeswoman Amanda Malkowski said in the statement to KDKA-TV and the Pittsburgh Post-Gazette.
Workers were charging ovens and pushing coke out of them as part of normal operations, Executive Vice President Scott Buckiso said at a news conference earlier this week.
“We want to reinforce that this investigation is in its early stages, and we will provide more information when we can,” Malkowski added. “Our focus remains on our employees and their families during this difficult time.”
She said company employees, agencies and experts have been reviewing video and interviewing workers.
“I thought something like this would take two to four to five months for it to unfold,” Calirton Mayor Rich Lattanzi said Friday. “I’m thinking what they found is a smoking gun.”
JoJo Burgess, who works at the plant and is mayor of nearby Washington, said he wants more information.
“Did someone know before it happened, so that they could have tried to stop the process?” he told KDKA-TV.
Bernie Hall, director of United Steelworkers District 10, said the union needs to learn more before speculating.
The explosion occurred around 11 a.m. Monday at the plant. Two people were initially reported missing, but the workers’ bodies were found in the rubble.
Killed were Timothy Quinn, 39, who lived with his disabled mother, and Bryan Dascani, 52, who was married and had two daughters, the Pittsburgh Post-Gazette reported.
Three other people remain in critical condition.
On Monday, U.S. Steel said the initial blast occurred inside the reversing room for batteries 13 and 14. Secondary explosions ensued but those blasts didn’t injure anyone.
U.S. Steel CEO Dave Burritt said local, state and federal personnel are investigating, including the U.S. Chemical Safety and Hazard Investigation Board.
On Tuesday, Gov. Josh Shapiro said during a news conference he wants Clairton and its surrounding communities to be protected. The blast could be felt miles away.
The Clairton plant settled a 2017 suit for $8.5 million over pollution, including $6.5 million to reduce soot emissions and noxious odors, CNN reported.
WTAE-TV uncovered past violations and injury reports at the plant over the past decades.
The Environmental Protection Agency’s Risk Management Program enforcement analysis found that over five years, the plant was listed in “high priority violation” of the Clean Air Act and 32 “formal enforcement actions.” This is four times more violations than at similar places at the same time.
The Occupational Safety and Health Administration found the plant had nine serious injury reports as of early 2024. They include trips and falls, resulting in broken bones or cuts.
There are around 1,300 workers at the plant.
“U.S. Steel had a record-setting safety performance in 2024 and an over 99% environmental compliance record. Safety is our top priority every single day,” the company said in a statement.
“Over the last five years, U. S. Steel has invested over $750 million in improvement projects at its Mon Valley Works facilities, including roughly $100 million annually being spent at the Clairton facility on environmental compliance.”
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.