Just before 1 a.m. on April 16, 2013, as-yet unidentified assailants launched an attack on the Metcalf substation in Silicon Valley. The attack lasted nearly an hour, disabling ten high-voltage transformers and three high-voltage transformer banks. Occurring just hours after the Boston Marathon bombings, the attack garnered little press coverage at the time and, as a federal investigation dragged on, details were slow to emerge. Beginning with an article published in Foreign Policy magazine in late 2013, information suggesting that the attack may have been the work of terrorists rather than vandals has started to come to light. In response to these revelations, group of four U.S. Senators today sent a letter to federal regulators calling for swift action to address the threat.
Earlier this week, the Wall Street Journal published a long article providing many details of the attack. In the article, former Federal Energy Regulatory Commission Chairman Jon Wellinghoff noted several pieces of evidence suggesting that the attack was carefully orchestrated. For example, before the attack began, someone lifted a large cover off an underground vault and cut communications cables, knocking out communications in the area around the substation and interfering with emergency response. More than 100 empty shell cases, likely from AK-47 assault rifles, were found in the area around the substation. None had fingerprints and military experts found small piles of rocks that may have been left by an advance scout to mark the best vantage points for the attack. The number of shell cases and the fact that the vault cover probably could not have been lifted by a single person suggest that multiple individuals were involved in the attack. Many of these details were corroborated in subsequent accounts from media outlets such as National Public Radio and Bay Area newspapers.