A gas valve failure caused the explosion at Clairton Coke Works on Monday morning that killed two people, U.S. Steel said Friday. Why it matters: The massive Mon Valley facility — one of the largest ...

The deadly blast at the U.S. Steel facility outside Pittsburgh was just the latest in a series of recent workplace accidents.

United States Steel Corp. said Friday the fatal blast that killed two workers at its Clairton Coke Works facility in ...

Flushing of a gas valve made during maintenance preparation may have led to the deadly explosion at the U.S. Steel Clairton Coke plant.