U.S. Steel released preliminary findings about the potential cause of Monday's deadly explosion at U.S. Steel Clairton Coke Works.

U.S. Steel on Friday pinned the blame for the deadly explosion Monday at the Clairton Coke Works on a valve failure that led to coke oven gas igniting, according to the company’s preliminary findings.

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.