A KQED review of thousands of 911 and dispatch calls from Oct. 8 found that first responders in Napa and Sonoma counties began responding to electrical incidents just before 4 p.m. As winds picked up, dispatchers discussed electrical problems more than 40 times between 7 and 10 p.m. At the same time, Sonoma County operators fielded dozens of 911 calls about sparking power lines and exploding transformers.

One unidentified woman called Sonoma County's 911 about an explosion at 9:22 p.m.

"A transformer blew, a PG&E transformer, and it lit up a whole window," she said. "It looks like a house is on fire at the end ... people are running down that way."

Cal Fire still hasn’t confirmed the cause of all the fires. But KQED's investigation found that these electrical problems sucked firefighting resources, leaving first responders short-staffed when larger fires broke out later. The power issues also delayed fire crews, who had to wait for utility workers to power down live lines.

The profusion of early fires also overwhelmed dispatch centers, not only preventing the public from reaching 911, but also hurting authorities’ ability to talk to one another.