One person has died, one person is unaccounted for and at least 10 are injured following an explosion at a U.S. Steel plant near Pittsburgh, Allegheny County Police Assistant Superintendent Victor Joseph said at a press conference Monday afternoon.

An explosion at a U.S. Steel plant south of Pittsburgh has killed two people and injured 10 others. One worker was rescued from the smoldering wreckage hours after Monday’s blast at Clairton Coke Works.

An explosion rocked the U.S. Steel Clairton Coke Works facility near Pittsburgh Monday, leaving people trapped beneath the rubble, officials said.