CSB Publishes Update for Coke Works Explosion Investigation

Yesterday the Chemical Safety Board announced the publication of their first update about their investigation of the August 11^th, 2025 explosion at the U.S. Steel Clairton Coke Works in Clairton, PA. That explosion killed two employees and seriously injuring five others. CSB announced their initiation of this investigation last month.

The update provides a description and history of the facility, as well as an overview of the process. It also provides a brief timeline of the incident. The Update concludes by outlining the ongoing investigation activities:

• Determining the cause and source of the gas release that led to the explosion,

• Metallurgical analysis of the cast iron coke oven gas valves,

• U.S. Steel’s use of cast iron in coke oven gas piping, and,

• U.S. Steel’s policies, procedures, and safety management systems.