Rescuers were continuing to search for one missing worker at the Clairton Coke Works more than five hours after mid-morning explosions rocked the Mon Valley plant. The blasts killed one person and injured 10.

A day after a deadly explosion rocked the Clairton Coke Works facility, Allegheny County officials confirmed that two men were killed and five others remain hospitalized in critical but stable condition as authorities continue to investigate the incident alongside federal and local partners.

Authorities said 10 other workers required hospital treatment — including five listed in critical but stable condition — after an explosion Monday morning at the U.S. Steel Clairton Coke Works. The cause of the blast has not been determined.