massive preemptive public safety power shutoff events have been controversial. pacific gas & electric, southern california edison and san diego gas & electric had preemptively shut off power to 800,000 electric customers to reduce the risk of wildfires by preventing electrical arcing in high winds from their above-ground power lines. while large areas were without power for days, people in fire danger areas had trouble getting information, and critical life support equipment would not work without backup power.