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

The deadly blast at the U.S. Steel facility outside Pittsburgh was just the latest in a series of recent workplace accidents.

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.