Massive power outage strikes San Francisco as system glitch warns of chaotic blackout

A routine operation at two San Francisco substations triggered a massive power outage Saturday morning that knocked out electricity to about 9,400 PG&E customers — while a separate system glitch mistakenly alerted roughly 120,000 customers that they had lost power. The blackout began around 9:45 a.m. when a protective device on the electrical system activated...