SAN FRANCISCO – Close to 200,000 Northern California residents, many of them left in the dark by a third power shutdown in a month, have been ordered to leave their homes as historic winds fueled an explosion of wildfires in the San Francisco Bay Area.

The state’s largest utility, Pacific Gas & Electric, shut off power to an estimated 2.3 million people across 38 counties starting Saturday evening in an effort to avoid having its equipment spark fires amid dry conditions and powerful winds.

A similar precautionary move did not prevent the Kincade Fire from igniting late Wednesday, and early indications point to malfunctioning PG&E equipment as the cause of it.

On Sunday afternoon, PG&E announced it's monitoring another extreme-wind event that could trigger yet another power outage Tuesday and Wednesday, the third such blackout in a week and fourth in October. Up to 32 counties in Northern and Central California could be affected.

The Kincade Fire has now grown to 54,298 acres and was only5% contained as of 7:10 p.m. PDT Sunday, forcing authorities to impose mandatory evacuations for 180,000 residents in Sonoma County, best known for its wine production.

Flames also flared on both sides of Interstate 80 near the Carquinez Bridge in Vallejo, 20 miles north of Oakland, forcing the freeway to be temporarily shut down in both directions and the nearby California State University Maritime Academy to be evacuated.

A stretch of two interstate highways was also closed for a while in the state capital of Sacramento because of a grass fire whose smoke impaired visibility for drivers.

California Gov. Gavin Newsom declared a statewide emergency as the extreme weather conditions significantly heightened the risk of wildfires .

Concerns that the winds could blow embers and spread the Kincade Fire across a major highway prompted the evacuation orders covering parts of Santa Rosa, a city of 175,000 that was devastated by wine country fires two years ago.

“This is the largest evacuation that any of us … can remember,” the Sonoma County Sheriff’s Office tweeted Sunday morning in English and Spanish, warning later that the winds were starting to whip up again.

The large expansion in the number of people told to leave their homes, from 90,000 Saturday night, reflected the increasingly dangerous conditions created by the winds picking up.

On Sunday morning, the National Weather Service reported wind gusts topped 90 mph in Healdsburg Hills North. Winds could lead to “erratic fire behavior” and send embers for miles, Cal Fire warned.

The wind event expected to peak early Sunday would likely be the strongest in several years, PG&E meteorologist Scott Strenfel said. Its effects were felt beyond the fire risk.

Downed trees and power lines caused an outage in Oakland impacting nearly 2,000 residents who were not part of PG&E's planed shutoff. And in Martinez, also in the East Bay, nine people at a farmers market were injured when strong winds toppled a 30-foot tree.

More than 3,400 firefighters with 352 engines and 10 helicopters were battling the Sonoma County blaze, which had destroyed 94 structures. No fatalities have been reported.

Sonoma County Sheriff Mark Essick said his deputies have encountered resistance from from some residents in the evacuation zone determined to stay in their homes, and he again made a call for them to heed warnings and leave. Essick also said the exodus has gone smoothly.

“Although I’ve heard people express concerns that we are evacuating too many people, I think those concerns are not valid at this point,” said Essick, who noted 24 people died in the 2017 fires.

As if a reminder of the threat the current fire represents were necessary, photos of the popular Soda Rock Winery outside Healdsburg engulfed in flames spread through social media Sunday. Some of the winery's buildings traced to 1869.

The cause of the fire remains under investigation. PG&E equipment has been blamed for some of California’s deadliest and most destructive wildfires the last two years, and the utility acknowledged a broken jumper wire was found on a transmission tower near where the Kincade Fire started.

The company said this third wave of blackouts would affect about 940,000 homes and businesses for 48 hours or longer. Most of the impacted customers are in the Bay Area, along with some in the Sierra foothills.

In Southern California, which was also the subject of preventive outages late last week, crews in the Santa Clarita area north of Los Angeles had made progress battling the Tick Fire.

That blaze, which began Thursday, was 70% contained after burning 4,615 acres and destroying 29 structures. The vast majority of the 50,000 residents who were forced to leave their homes have been allowed to return as winds tapered off.

Contributing: Kristin Lam, USA TODAY; The Associated Press.