https://en.wikipedia.org/wiki/Metcalf_sniper_attack
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.
https://www.latimes.com/nation/la-na-grid-attack-20140211-story.html