One person has died and dozens are reportedly injured or trapped under rubble following an explosion at a U.S. Steel plant near Pittsburgh on Monday, an Allegheny County emergency services spokesperson told the Associated Press.

U.S. Steel says it believes a gas valve failure led to the explosion Monday morning at its Clairton Coke Works, in which two workers died and 10 others were injured.

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