COOLIDGE, Ariz. — In 2021, a leak in a Kinder Morgan gas pipeline caused an explosion that leveled a Coolidge farmhouse and left two people dead. Now, investigators know that a mistake in company records eventually allowed for the pipeline's failure.
A fracture along the pipe's weld was what set off the explosion, a new report from the National Transportation Safety Board determined. But that fracture was caused by something that could have been caught sooner.
VERSIÓN EN ESPAÑOL: Investigadores han determinado la causa de la explosión de la línea de gas en Coolidge en el 2021
Tenting in the spiral wrap tape that surrounded the pipe allowed for high-PH soil and moisture to seep into the metal, eventually breaking it in a process called "stress corrosion cracking."
According to the NTSB, spiral wrap tape is "known by the pipeline industry to be more vulnerable than other coating types," to that type of corrosion.
However, Kinder Morgan was not prepared for the threat due to a mistake in their records. The NTSB found that the pipeline was incorrectly listed as being coated with fusion-bonded epoxy -- a much stronger substance.
As a result, the risk assessments that the company conducted in the area didn't accurately search for the signs of stress corrosion cracking.
It would prove to be a fatal mistake.
On Aug. 15, 2021, the pipeline ruptured and exploded. The explosion destroyed a nearby farmhouse that was occupied by a local family, killing a 14-year-old girl and her father.
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"Contributing to the rupture was Kinder Morgan’s failure to record the correct coating type used for this segment of pipeline, leading to a risk assessment that did not fully identify the risk of stress corrosion cracking," the NTSB concluded.
Since then, Kinder Morgan has reportedly corrected its coating data and created a new procedure for preventing such mistakes in the future. The company also tested 19 miles of pipeline in the area, excavating four areas for repair and improvement.
The pipeline restarted operations in February 2023, and a spokesperson for Kinder Morgan provided 12News with the following statement:
"The safety of the community continues to be our primary concern, and we safely resumed operations today. We continue to fully cooperate and appreciate the important role that the NTSB and PHMSA have taken throughout this investigation, and we will continue to address any concerns that are identified through this process."
You can read the NTSB's full 11-page report below:
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