CLAIRTON, Pa. — U.S. Steel has released new details on what investigators believe caused the explosion at the Clairton Coke Works plant that killed 2 people and injured 10 others.
PREVIOUS COVERAGE >>> 2 dead, 10 injured in explosion at US Steel Clairton Coke Works plant
On Friday at 4 p.m., U.S. Steel said an investigation conducted by third-party experts has revealed that the explosion happened while crews were flushing a gas valve in preparation for planned maintenance.
PHOTOS: Explosion at U.S. Steel Clairton Works Plant
Investigators learned pressure was building inside the valve, which caused it to fail. The failure caused coke oven gas to fill the area, which led to the explosion after it found a source of ignition.
“We want to reinforce that this investigation is in its early stages, and we will provide more information when we can. Our focus remains on our employees and their families during this difficult time,” a spokesperson for U.S. Steel said.
Timothy Quinn and Steven Menefee were killed in the explosion.
Of the 10 workers who were injured, 7 have been discharged.
The Allegheny Health Department has deployed Mobile Air Units in the Mon Valley to monitor pollutants.
U.S. Steel CEO David Burritt said the plant is now safe to operate.
Investigators continue to review surveillance video and interview employees as they work to find answers.
“If they put that statement out, I would agree with what they’ve said,” Andrew Macey told Channel 11. He’s a mechanical repairman in the utilities department at the Clairton Works.
In his more than three decades there, Macey says he’s only seen gas-related incidents two other times. Neither resulted in fatalities.
“This is the first one that’s really the most tragic because of having two fatalities and injuries to other co-workers,” Macey said.
According to Macey, if workers notice something is wrong, they have the authority to stop.
“The work that they were doing was done according to safety procedures in place, but something failed. Something happened, whether it was human error or mechanical.”
Clairton Mayor Richard Lattanzi is a former steelworker. He told Channel 11 U.S. Steel’s explanation seems “plausible.”
We also reached out to the Vice President of USW 1557. He had no comment on the findings.
Download the FREE WPXI News app for breaking news alerts.
Follow Channel 11 News on Facebook and Twitter. | Watch WPXI NOW
©2025 Cox Media Group
/cloudfront-us-east-1.images.arcpublishing.com/cmg/XCUXZC2XYZHCRGNNGKFEX6U3LQ.png)
