Assault on California Power Station Raises Alarm on Potential for Terrorism

SAN JOSE, Calif.—The attack began just before 1 a.m. on April 16 last year, when someone slipped into an underground vault not far from a busy freeway and cut telephone cables.

Within half an hour, snipers opened fire on a nearby electrical substation. Shooting for 19 minutes, they surgically knocked out 17 giant transformers that funnel power to Silicon Valley. A minute before a police car arrived, the shooters disappeared into the night.

To avoid a blackout, electric-grid officials rerouted power around the site and asked power plants in Silicon Valley to produce more electricity. But it took utility workers 27 days to make repairs and bring the substation back to life.

Nobody has been arrested or charged in the attack at PG&E Corp.’s PCG -0.56% Metcalf transmission substation. It is an incident of which few Americans are aware. But one former federal regulator is calling it a terrorist act that, if it were widely replicated across the country, could take down the U.S. electric grid and black out much of the country.

The attack was “the most significant incident of domestic terrorism involving the grid that has ever occurred” in the U.S., said Jon Wellinghoff, who was chairman of the Federal Energy Regulatory Commission at the time.

The Wall Street Journal assembled a chronology of the Metcalf attack from filings PG&E made to state and federal regulators; from other documents including a video released by the Santa Clara County Sheriff’s Department; and from interviews, including with Mr. Wellinghoff.

The 64-year-old Nevadan, who was appointed to FERC in 2006 by President George W. Bush and stepped down in November, said he gave closed-door, high-level briefings to federal agencies, Congress and the White House last year. As months have passed without arrests, he said, he has grown increasingly concerned that an even larger attack could be in the works. He said he was going public about the incident out of concern that national security is at risk and critical electric-grid sites aren’t adequately protected.

The Federal Bureau of Investigation doesn’t think a terrorist organization caused the Metcalf attack, said a spokesman for the FBI in San Francisco. Investigators are “continuing to sift through the evidence,” he said.

Some people in the utility industry share Mr. Wellinghoff’s concerns, including a former official at PG&E, Metcalf’s owner, who told an industry gathering in November he feared the incident could have been a dress rehearsal for a larger event.

“This wasn’t an incident where Billy-Bob and Joe decided, after a few brewskis, to come in and shoot up a substation,” Mark Johnson, retired vice president of transmission for PG&E, told the utility security conference, according to a video of his presentation. “This was an event that was well thought out, well planned and they targeted certain components.” When reached, Mr. Johnson declined to comment further.

A spokesman for PG&E said the company takes all incidents seriously but declined to discuss the Metcalf event in detail for fear of giving information to potential copycats. “We won’t speculate about the motives” of the attackers, added the spokesman, Brian Swanson. He said PG&E has increased security measures.

Originally published at the Wall Street Journal