Attack on the Metcalf Substation Highlights Grid Vulnerabilities

On April 16, 2013, two armed individuals opened fire on Pacific Gas and Electric’s (PG&E) Metcalf electrical substation, located about 15 miles southeast of San Jose. The shooters positioned themselves 30–40 yards outside the fence in the scrubland near Coyote Creek and, after a brief flash of light was captured on a security camera, discharged high-powered rifles into a row of truck-size transformers.

New York Times

The assault began at 1:31 a.m. and lasted roughly ten minutes, during which approximately 120 rounds struck the facility. The gunfire targeted the transformers’ cooling fins, allowing roughly 52,000 gallons of oil to drain slowly and delaying an immediate failure alarm. Seventeen of the substation’s transformers were disabled before the shooters ceased fire at 1:50 a.m. Police arrived at 1:51 a.m. but found no evidence; the damage was not fully recognized until a utility worker inspected the site at 3:15 a.m.

New York Times

PG&E’s president promptly notified the Federal Energy Regulatory Commission (FERC). Jon Wellinghoff, then chairman of FERC, traveled to Metcalf a few days later. He reported that investigators recovered no fingerprints on shell casings and found no tracks in the surrounding dust, leaving the motive uncertain—speculation ranged from a random act to a disgruntled employee.

New York Times

Because power was quickly rerouted, the Bay Area avoided a widespread blackout despite the loss of 17 transformers. The incident underscored the fragility of critical infrastructure that supplies electricity to major technology firms in Silicon Valley.

New York Times

The Metcalf attack revealed how a relatively small, coordinated assault can threaten the bulk-power system. It prompted renewed calls for enhanced physical security at high-voltage facilities and highlighted the need for robust communication links between utilities and regulatory agencies to detect and respond to such threats promptly.

New York Times