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.

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.

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.