PORTLAND, Ore. -- Fire investigators have determined a massive explosion that ripped through a building in Northwest Portland was caused by an excavator that struck a steel gas line.
The impact from the excavator pulled the pipe out of a fitting that was further underground, which caused the natural gas leak. The natural gas then traveled underground near the pipe and into the basement of a bagel shop on busy Northwest 23rd Avenue.
It is not clear what ignited the gas, leading to the explosion.
“Because the power was on to that building and due to the number of possible electrical and other ignition sources in the basement, fire investigators are classifying the specific ignition source as unknown at this time,” wrote Portland Fire & Rescue in a summary of its investigative findings.
Local, state and federal fire officials helped in the investigation into the October 19 blast. Investigators ruled the explosion to be “unintentional in nature.”
Eight people were injured in the natural gas explosion, including firefighters and police officers. None of the injuries were life threatening.