PG&E told regulators in a report filed Thursday that a broken jumper cable on a transmission tower may have been to blame for the Kincade Fire on Wednesday, confirming that the company had not turned off power to its highest voltage equipment during shutoffs that began earlier that day.

According to the preliminary report, the utility learned at 9:20 p.m. that there was a problem involving a 230,000-volt line and that an automated device could not re-establish service – thus forcing an outage and likely sparking the fire that swelled to 10,000 acres.

The problem was discovered after the fire, the utility says, when its crews arrived and found that Cal Fire taped off an area at the base of one of its transmission towers, number 001/006.

“On site Cal Fire personnel brought to the (PG&E technician’s) attention what appeared to be a broken jumper on the same tower,” the company’s report to regulators said.

A jumper is a short piece of wire – not unlike an extension cord – that is normally loose and serves to send power around parts of a transmission tower.

That regulatory report came as records show that PG&E cut power in the area some 23 minutes after the Kincade Fire was reported as having erupted and seven hours after it shut down power to nearby communities, records reviewed by the Investigative Unit show.

The wind-whipped blaze has now consumed more than 10,000 acres. It was first reported, according to county fire radio traffic, at 9:25 p.m., near a geothermal complex known as the Geysers.

“A vegetation fire reported in the Geysers, it’s going to be on John Kincade Road,” one dispatcher says. Less than a minute later, the dispatcher adds an ominous warning: “Also, possible power lines down in the area … all units acknowledge life safety hazard.”

PG&E records show it turned off power at 9:48 p.m. as part of its shutoff program. The records also show it shut off power nearby seven hours earlier to other parts of Sonoma County, including one area just two miles away from where the fire was first reported.

Meanwhile, inspection records reviewed by NBC Bay Area’s Investigative Unit show that as of last spring, PG&E had completed repairs on more than 30 problems it found on the system of transmission lines within a three-mile radius of the geothermal complex.

NBC Bay Area reached out to Calpine Corp., which operates the nearby geothermal power plants, but has not heard back.