U.S. Steel is making changes to improve safety following the deadly explosion at Clairton Coke Works in August.
Days after the Aug. 11 incident, U.S. Steel released preliminary findings from a third-party firm.
The investigation revealed that excessive pressure built up in a gas valve that was being flushed, causing it to fail, U.S. Steel said. That led to coke oven gas filling up the area and, ultimately, an explosion…