Once again, PG&E’s electrical equipment is under suspicion as the possible cause of a devastating wildfire, even after the embattled utility subjected homes and businesses to widespread blackouts to keep its lines from sparking another inferno amid high winds.

Questions are swirling around the embattled utility after PG&E disclosed to state regulators that a transmission line it had decided did not need to be turned off suffered an outage as wind gusts over 40 mph buffeted the oaks and dry grasses covering the hills north of the Sonoma County town of Geyserville.

“It’s troubling beyond belief,” said state Sen. Jerry Hill, D-San Mateo, whose district includes a neighborhood where a 2010 PG&E gas pipe explosion killed eight people and led to criminal convictions for the utility over safety violations. “You see this accumulation of failures.”

The California Department of Forestry and Fire Protection continues to investigate the cause of the Kincade Fire, and Pacific Gas and Electric would only say Friday that it is continuing to investigate the issue with the transmission line and that its disclosure Thursday was preliminary. Company officials declined to answer further questions.

The Kincade Fire erupted during fierce winds about 9:24 p.m. Wednesday near The Geysers, the world’s largest complex of geothermal plants where steam from deep in the ground has been tapped for nearly a century to produce electricity.

PG&E said in its filing with regulators that at 9:20 p.m. Wednesday, a 230,000-volt transmission line in that area suffered an “outage” when safety equipment tripped like a household circuit breaker.

Firefighters roped off the area around the transmission tower and showed a utility line inspector who arrived at the site the next morning “what appeared to be a broken jumper” on it. A jumper is a line that connects transmission wire segments around the insulated connection points to the towers.

Such a failure could certainly have produced significant arcing or sparks that might have ignited a fire, said James Orosz, an electrical engineer with Robson Forensic who formerly worked for Con Edison.

“If that were to become broken or disconnected, it could cause an arcing condition,” Orosz said, a situation where electric current moves through the air like a static spark from shuffling across a carpet and reaching for a metal door knob. With a 230,000-volt line, however, that spark is “thousands of degrees.”

“It will melt metal, and cause a tremendous amount of light and heat,” Orosz said. “And that’s where the concern comes in with these fires, this molten metal falling onto dry ground where there’s combustible material.”

PG&E said it had inspected the tower in question earlier this year as part of its Wildfire Safety Inspection Program.

But the utility also decided to leave the transmission line energized even as it turned off others to avoid wildfire risk, raising further questions. PG&E said “forecast weather conditions, particularly wind speeds, did not trigger” a need for shutting off transmission lines.

“The wind speeds of concern for transmission lines are higher than those for distribution” lines, PG&E said.

But PG&E would not answer questions Friday about what its standards are for the different types of lines. Neither would the California Public Utilities Commission, which referred questions to PG&E.

A 230,000-volt line is a mid-level transmission line, designed to carry high voltage — from 100,000 to 750,000 volts — over long distances, Orosz said. Distribution lines then carry tens of thousands of volts from those transmission lines into neighborhoods.

According to the National Weather Service, the Geyserville area had sustained winds of 21 mph around 9:30 p.m. Wednesday with gusts up to 42 mph. Winds peaked at midnight, with sustained winds of 52 mph with gusts up to 76 mph. Sustained winds of 39-54 mph are considered gale force, while a hurricane has sustained winds over 74 mph.

The Camp Fire began when a PG&E transmission tower east of Paradise failed as winds gusted to 50 mph the morning of Nov. 8, 2018. A 115,000-volt transmission line was believed to have broken loose, striking the metal tower and showering molten metal on dry brush below.

Gov. Gavin Newsom has blamed PG&E for the forced blackouts and fires, arguing years of shoddy maintenance left its electrical power system in poor shape and unable to effectively limit wildfire damage.

Hill said he hopes the federal judges overseeing PG&E’s probation for San Bruno and bankruptcy proceeding force a management takeover.

“I think this calls for drastic action and quick action,” Hill said. “I think for the protection of California and its residents, one should replace its current ineffective and irresponsible management. It is just beyond belief that this company is as bad as it’s been and continues to be.”