The preliminary findings say how the company believes the explosion occurred. A union statement cautioned the investigation ...

The deadly explosion at Clairton Coke Works near Pittsburgh occurred when a gas valve was flushed before planned maintenance, ...

U.S. Steel released preliminary findings about the potential cause of Monday's deadly explosion at U.S. Steel Clairton Coke ...

U.S. Steel says preparations for a routine maintenance task may have led to an explosion at a U.S. Steel coal-processing ...

"Pressure built inside the valve, leading to valve failure and coke oven gas filling the area and ultimately exploding when ...

Allegheny County is boosting air monitoring after a deadly explosion at U.S. Steel’s Clairton Coke Works, a plant with a ...

The explosion happened when workers were flushing a gas valve in preparation for maintenance on two of the plant's coke oven ...

U.S. Steel has released new details on what investigators believe caused the explosion at the Clairton Coke Works plant that ...