They came after midnight, two or more armed individuals so deft that they cut telecommunication cables in an underground vault and outsmarted security cameras and motion sensors at the power substation in a remote corner of Santa Clara County.
At daylight, FBI agents began poring over time-lapse photographs from the surveillance cameras. But the photos revealed only staccato muzzle flashes from a semiautomatic weapon and sparks as shots hit rows of transformers. There was not a face, not a shadow, of who was doing the firing.
The military-style raid on April 16 knocked out 17 giant transformers at the Metcalf Transmission Substation, which feeds power to Silicon Valley. The FBI is still working the case, and agents say they are confident it was not the work of terrorists.
What they do not have is a motive, fingerprints or suspects. But theories are piling up.
No one was injured. But it took utility crews nearly a month to repair the damage.
Four Democratic senators, including California’s Dianne Feinstein, chairwoman of the Senate Intelligence Committee, and Senate Majority Leader Harry Reid of Nevada, on Friday urged utility regulators to beef up security at power plants and substations around the nation. They said the “sophisticated attack” was a “wake-up call” about threats to crucial infrastructure.
Counter-terrorism officials have repeatedly warned of a potential cyberattack that could disable or crash electric grids, but the assault 15 miles southeast of San Jose was decidedly low-tech.
Law enforcement sources and others briefed on the investigation say the gunmen fired 120 rounds from a high-powered rifle and that nearly every shot hit the transformers 40 yards away in a 20-minute period.
The transformers began to leak tens of thousands of gallons of oil. They overheated and shut down, but did not explode.
Officials say the attackers brought night-vision scopes for their weapons, used heavy wire cutters to snip fiber-optic cables in a below-ground bunker and knew the specific manholes to open to reach the right cables.
The team briefly disabled the 911 emergency system and phone lines. They set off a motion detector by the fence before leaving, but the facility sits beside U.S. 101, a convenient escape route.
Source: LA Times