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So how DID a pipe-break east of 82nd blow out all the electric power west to the river?

COURTESY OF GARY SARGENT  - NW Natural Gas supervisors devise a plan to shut of the natural gas spewing from a ruptured gas main.
Construction contractors, drilling a horizontal hole across S.E. Foster Road at 102nd Avenue, hit a natural gas main at 5:17 p.m. on Tuesday, May 15.

While usually something like this is just a localized incident, this particular underground industrial accident blacked out Inner Southeast Portland all the way to the Willamette River.

Responding Portland Fire & Rescue officials called it a "significant" gas line rupture, and ordered evacuations from businesses and homes along Foster Road, from S.E. 101st to 104th Avenue that evening.

Gary Sargent, Sr., and his crew at Sargent's Motorsports, on the northeast corner of the affected intersection, watched the incident unfold, took some pictures – and soon, they were told to run for their lives.

"We were getting ready to close up for the day when it happened, just starting to bring in our motorcycles on display in front of the store; my nephew said he smelled natural gas," said Sargent the following day. "We have an evacuation plan – and then I also smelled it; I thought natural gas was somehow leaking here in our building, and we all got out."

In front of the store, and looking across S.E. Foster Road, his view of what was happening was distorted by a shimmering diffraction in the air, caused by natural gas belching out of what turned out to be a 4 inch main, buried below the pavement near his property line.

"This wasn't just a 'leak', as some have reported, but a tremendous volume of natural gas billowing from the ground," Sargent recalled.

Soon Portland Fire & Rescue (PF&R) Lents Station Engine 11 was on hand, along with NW Natural Gas workers. "After they used a meter to measure the gas concentration in our building, they said it was a 'potential bomb, ready to go off' – and they quickly moved us more than a block to the north," Sargent said.

With their personal vehicles all parked within the spewing gas cloud, none of his staff could leave until they were given the "all clear" at about 9 p.m. that evening.

What Sargent didn't find out until later, was that a PF&R Battalion Chief had called Portland General Electric (PGE), asking them to shut down the massive electrical substation across the street, out of fear that just one spark could cause a disaster.

"The electrical outage began at 7:26 p.m. because any kind of spark from the equipment could have ignited the natural gas," explained PGE spokesperson Steve Corson. "No sparks were seen at the substation, but if a fuse had tripped, or a switch had operated, it could have created a spark."

Some five miles west of the incident, 36,000 residents and businesses in portions of the Reed, Eastmoreland, Sellwood, Brooklyn, Creston-Kenilworth, and Westmoreland neighborhoods lost their electric power just as the sun set. Traffic signals went out along S.E. McLoughlin Boulevard, from the north end of the viaduct near OMSI south to the Clackamas County line.

While the TriMet MAX Light Rail Orange Line kept running – it's powered by its own independent circuit – elevators and station lighting went out at the Bybee Boulevard MAX Station.

Why was so much of Inner Southeast affected by this? "Shutting down that substation had a cascading effect, because it routes electricity to several major electrical distribution 'feeder' lines; and each 'feeder' serves from hundreds to thousands of customers," explained Corson.

There hasn't been an official reason given why almost two hours passed before the request to cut the power came in. Corson surmised, "Gas leaks are cumulative over time; and as time went by, the gas concentration may have increased in that area.

"Many customers were back on in an hour; power was restored to the westernmost affected neighborhoods an hour and ten minutes later, and most power was back on by 10 p.m.," Corson said, adding that at about 8:30 p.m., a NW Natural Gas crew had managed to seal the broken gas main.

Sargent recalled, "They waited a while for the gas to dissipate, and then allowed us back into our shop, after they'd checked it, at about 9 p.m.

"Those three hours were a frightening time," Sargent recalled, "But fortunately, our family business was okay."

How did this accident occur? "A person from the contracting company said they were driving a pipe under the road, from south to north," recounted Sargent. "Apparently, these directional, horizontal, under-street drilling rigs can 'steer' the pipe. In this case, I was told as it neared the northern curb, the drilling shaft went up dramatically [by itself], and ruptured the gas main."

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