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

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.

The explosion took place at the US Steel Clairton Coke Works plant, located south of Pittsburgh, Pennsylvania.