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.

An explosion occurred Monday at a steel factory in Clairton, Pennsylvania, authorities said. A spokesperson for Allegheny County said a rescue operation was underway at U.S. Steel Clairton Coke Works for people trapped under the rubble.

An explosion at a U.S. Steel plant near Pittsburgh has left dozens injured or trapped under the rubble, with emergency workers on site trying to rescue them.