CLAIRTON, Pa. (AP) — Investigators are working to determine the cause of an explosion that rocked a steel plant outside Pittsburgh, leaving two dead and more than 10 others injured, including a person who was rescued from the smoldering rubble after hours of being trapped.

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.

• At least one person is dead, 10 injured and one unaccounted for in an explosion at the Clairton Coke Works in Pittsburgh, Pennsylvania. The cause of the explosion is unknown and officials are investigating, US Steel said.