On August 15, 2021, about 5:29 a.m. local time, a 30-inch-diameter natural gas transmission pipeline owned and operated by Kinder Morgan, Inc., ruptured in a rural area of Coolidge, Arizona. The rupture resulted in the release of natural gas vapor that ignited and exploded. The explosion and gas-fed fire destroyed a farmhouse about 451 feet away, killing two of the three occupants and seriously injuring the other.
We determined that the probable cause of the August 15, 2021, pipeline rupture in Coolidge, Arizona, was tented tape wrap leading to stress corrosion cracking, a fracture at a longitudinal seam weld, and subsequent rupture of the pipe. 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.