Quick Take: A few years back, a friend of mine served on a Department of Homeland Security committee on infrastructure protection. They heard lots about cyber threats. But the thing that worried them the most was the “Seven Bullets Theory.” That’s the idea that a terrorist group could shut down the entire East Coast grid with just seven well-placed bullets at seven different substations.

A miniature version of this scenario took place earlier this week in Silicon Valley. It prompts me to remind utilities not to let the current emphasis on cybersecurity cause them to overlook the very real and important issues around physical security. – Jesse Berst

Rifle shots damaged a Pacific Gas & Electric substation Tuesday morning, causing the California Independent System Operator to call for power conservation.

Gunfire was heard in the early morning at a substation near San Jose. At approximately the same time, someone cut nearby fiber optic cables, disabling the local 911 service. Investigators think the two acts of sabotage are linked.

The saboteur’s objective appears to have been “shutting down the system,” Sheriff Laurie Smith said at an afternoon news conference at the substation, as reported by station KTVU. PG&E officials told the sheriff’s office that the substation’s security fence had been breached, at least five transformers had been damaged and that hazardous materials had spilled, Stenderup said.

Damage from the high-powered rifle shots was severe enough that the transformer will have to be replaced.

Electricity has not been interrupted so far, according to a Cal-ISO spokesman, since customers have responded to the call to save electricity.

Jesse Berst is the founder and chief analyst of Smart Grid News.com, the industry’s oldest and largest smart grid site. A frequent keynoter at industry events in the U.S. and abroad, he also serves on advisory committees for Pacific Northwest National Laboratory and the Institute for Electric Efficiency. He often provides strategic consulting to large corporations and venture-backed startups. He is a member of the advisory boards of GridGlo and Calico Energy Services.