Now that power has been restored to 1.4 million San Diego Gas & Electric customers, state and federal regulators are focused on figuring out who’s responsible for San Diego’s massive blackout and what measures, if any, could have prevented it.
SDG&E says a cascading series of failures caused the collapse of the region’s power grid Thursday afternoon. The utility says it was started by a single repair job gone wrong more than a hundred miles away in Arizona. Here’s a rundown of four major questions that haven’t been fully answered:
What exactly went wrong?