More than 5,000 people without power in Castro Valley, Calif., after reports of large boom heard in area.
As reported on Twitter by @abc7newsBayArea, over 5,000 customers were without power in Castro Valley near San Miguel & Somerset Ave just after a huge and loud boom was heard across the area.
Castro Valley is a census-designated place in Alameda County, California. As of the 2000 census, it is the fifth most populous unincorporated area in California, and the twenty-third in the United States.
In 2010, heat caused a blackout in Castro Valley. Last year, high winds were to blame for power outages of over 3000 homes there. This year it is a loud and mysterious boom (transformer explosion?)