SEATTLE – State regulators now say it could take a year to solve the mystery of what prompted the explosion in a North Seattle neighborhood, and damage was far more localized than previously reported.
The explosion, on September 26, destroyed a home in the Pinehurst neighborhood and injured a husband and wife. Puget Sound Energy investigators performed three surveys of their system within a five-mile radius of the explosion in the days after and announced ten leaks were found.
But Joe Subsits, the Chief Pipeline Safety Engineer for the Washington State Utilities and Transportation Commission, said they are focusing only on four particular leaks. Subsits said the leaks have the same signature, and the other discovered leaks were likely related to maintenance issues.
Subsits said evidence shows the four leaks all occurred “within a relatively short period of time.” He said that eliminates potential theories about what went wrong.
The UTC has requested the pipe, near the destroyed home, to submit it for lab tests. Subsits said the agency is still investigating PSE’s claim that the blast was caused by a downed power tree and power line. However, he said the agency is also investigating whether lightning and other high energy sources may have caused the leaks. There was a storm in the area around the same time the tree and line came down.