A huge electricity outage hit San Francisco on Saturday, leaving 130,000 residents without power and prompting city authorities to ask residents to stay home, according to the utility provider and the mayor. Large parts of the west coast tech hub, which has a population of more than 800,000 people, were plunged into darkness with disruptions to public transport and many traffic lights not working on a busy Christmas shopping weekend. “We are working with first responders and city officials on an...