Deadly U.S. Steel Clairton Coke Works explosion "should never have happened," report says

The U.S. Chemical Safety Board has released its final report into the deadly explosion at U.S. Steel's Clairton Coke Plant, finding it was the result of multiple preventable safety issues.

The report, released a day shy of one year since the explosion, faults the company, saying the explosion that killed Timothy Quinn and Steven Menefee and injured 11 others "should never have happened."

It cites the outcome of the deadly explosion being the result of the absence of a formalized procedure, the proximity of buildings employees work out of to where dangerous processes take place, and what the report refers to as an ineffective process safety management system.

"This incident was the result of workers routinely performing a task incorrectly over a period of years until it ultimately led to a catastrophic explosion," CSB Board Member Sylvia Johnson said. "Companies must outline procedures for any task that could potentially cause harm to workers and make sure that workers are fully trained on those procedures." 

Drew Sahli has been in charge of the investigation that produced Monday's report. It faults U.S. Steel for not having a formal procedure for a safe or proper way to complete the specific valve-cleaning process that caused the explosion. 

Workers from U.S. Steel and its contractor MPW Industrial Services were cleaning a 70-year-old valve when the valve broke, leading to coke oven gas igniting and exploding. As KDKA was the first to report in the weeks following the explosion, workers had used water and significantly overpressurized the valve, leading to its failure.  

"There was no procedure describing the correct or proper or safe way to do that operation, and unfortunately, the operation was done in such a way that directly caused the valve to fail," Sahli said. 

In the days and weeks before the explosion, investigators say it's what wasn't thought of that helped result in the explosion.

"Nobody ever sat around and said, 'Hey, is it a good idea to be doing this? This valve is rated for 50 pounds of pressure. Is it a good idea to hook up a [water] pump truck capable of producing far more than 50 pounds?'" said Drew Sahli, the investigator in charge of putting together the report for the Chemical Safety Board. 

The CSB report says workers had been cleaning the valves incorrectly for years. 

When asked why it had not failed before the explosion, Sahli said he doesn't have a solid answer, but that they do know for the valve to fail, it had to have been closed or nearly closed. That would prevent the water that was being used to clean the valve from getting out. The board concluded that a formal procedure for using water to clean valves wasn't drawn up despite U.S. Steel management being aware of and endorsing the practice. 

"The second safety issue is the longest one in the report, and that one talks about what's called facility siting," Sahli said. 

In short, it meant U.S. Steel didn't put enough distance between its coke batteries and buildings where people work out of. The two men who died were in or near control rooms located above the coke oven piping, and a break room was above it too. 

"When buildings are occupied by personnel, they must be adequately designed or located to protect the personnel or equipment from fires, explosions, or toxic releases," Sahli said. "Had these buildings been located in a different area of the facility, away from coke batteries, this incident could have been far less severe."

He explained that U.S. Steel could have taken action to identify and fix the issue. 

"The history of this issue at Clairton is that the companies had multiple opportunities in the past to think about this topic, and unfortunately, the company has chosen not to do that," he said. 

U.S. Steel didn't act because it believed it wasn't required to do so, Sahli said. Whether the reason is valid has been disputed. 

It connects to the third safety issue the report says resulted in the explosion — what they call process safety management systems.

"Maybe you weren't required to do it by regulation, but you should have done it anyway, because now you have two employees who were fatally injured during this incident, and had you done all of these activities voluntarily, they might still be with us," Sahli said.   

The Chemical Safety Board made multiple recommendations.

They include evaluating those distances between buildings and hazardous processes, developing a written procedure for washing valves with pressurized water, and developing a comprehensive process safety management system.

In a statement to KDKA, U.S. Steel said, "We appreciate the work of the Chemical Safety Board contained in its Final Report and will thoroughly review its recommendations."  

They also outlined several safety protocols they say they have already strengthened, including establishing standardized best practices for valve cleaning, improving their management of change program and having workers complete comprehensive training related to those changes.

As for Tuesday's remembrance of the explosion, along with lowering flags and a moment of silence, U.S. Steel says workers will gather for safety discussions, the company saying the best way to honor their fallen colleagues is to make sure everyone returns home in the future.

A company spokesperson said, "As we honor their memory, and those of others we have lost, we also reflect on the responsibility we all share to protect one another and ensure safety remains at the center of everything we do." 

The spokesperson said they will remember their colleagues and keep their families and loved ones in their thoughts.