With PG&E's announcement earlier this week that one of its power lines is under investigation as the cause of yet another destructive Northern California wildfire, attention has focused on the company's account that nine and a half hours elapsed after the first indication of trouble in the Feather River Canyon before one of the company's field workers reached the spot where a small fire was beginning to spread.

In a series of statements, including public comments from the utility's CEO, PG&E has blamed the delay on the worker's difficulty accessing the remote location where a tree had fallen on a power line and ignited the blaze that turned into the Dixie Fire.

But one of the prosecutors investigating the company's possible role in starting the Dixie Fire, which had burned more than 100,000 acres as of early Thursday, said the utility did not consider a power outage it had detected in the area early on July 13 to be a high-priority issue.

As a result, said Butte County District Attorney Mike Ramsey, the worker assigned to investigate the outage did not arrive in the area until as much as four hours after the the problem was detected.

That's just one in a series of delays and obstacles that together may have turned a minor incident into an inferno that has raged through the northern Sierra Nevada forests for 10 days.

In an electrical incident report to state utility regulators, PG&E said the first indication of trouble the day the fire started, July 13, was a 7 a.m. power outage at Cresta Dam. The dam is part of the company's complex of hydropower facilities on the North Fork of the Feather River, northeast of Oroville.

Ramsey, whose agency is investigating the incident alongside Cal Fire and the Plumas County District Attorney's Office, said the utility's response was delayed in part because the initial power outage was not considered a high-priority issue.

Ramsey said in an interview earlier this week that PG&E issued a "work ticket" after a remote monitoring system detected the problem at the dam.

"They put in a ticket — not a high-priority ticket, just a regular ticket, for a lineman in Chico to go check on it," Ramsey said. First, though, he had "other things to do — higher-priority tickets." Ramsey estimated the worker got to Cresta Dam about 10:30 or 11 a.m., as much as four hours after the power problem there had been flagged.

Once at the dam, Ramsey said, the worker needed to scout for the source of the power problem.

According to PG&E's account, he spotted what appeared to be a blown fuse on a power line across the Feather River and hundreds of feet up the canyon's precipitous slope. The site of the potential problem was just a quarter-mile from the dam as the crow flies, but it would take the worker hours to reach it.

To get there, he had to drive back down Highway 70 to the community of Pulga, where the route crosses the river. Then he had to drive about 10 miles up Camp Creek Road, a one-lane dirt road that passes the spot where the a PG&E transmission line started the Camp Fire early the morning of Nov. 8, 2018.

The trip up the steep, winding road would have been slow under any conditions. Describing the character of the route the worker traveled, Ramsey said, "There's an old statement, 'They're barely passable — not even jackass-able."

Eight miles up the road — still well short of the power line segment with the apparent blown fuse — the driver encountered a roadblock: a Butte County public works crew repairing a bridge.

"He was turned back there," Ramsey said. "They told him, nah, it's going to be at least a couple, two and a half hours" before they'd be done with the work.

Josh Pack, the county's director of public works, said the crew was working to repair "significant damage" to the one-lane span that had been reported on July 9. Pack said the bridge deck had suffered "multiple failures," likely due to an oversized vehicle that had used the span.

Unable to cross the bridge for the time being, the PG&E worker turned around and drove all the way back down to Highway 70, then another six miles back toward Oroville to a spot where he'd get better radio reception.

Ramsey said the worker discussed with a dispatcher coming back to Chico to do other work, but given the extra travel time that would add, he decided to wait for the bridge on Camp Creek Road to open. It wasn't until 4:30 p.m. that the worker finally made it up to and over the bridge and reached the spot where trouble was unfolding.

Ramsey echoed PG&E's account that once the worker reached the scene, he discovered a small fire on the ground near a tree that had fallen onto the power lines. Fuses had blown on two of the three lines running across the tops of the poles at the site, Ramsey said, but the third line was apparently still live and may have helped ignite the fire.

Ramsey said the worker attempted to call the fire in to a PG&E dispatcher via radio, but got no response. He then attempted to put out the fire, which was spreading slowly on a steep slope below the road, by himself.

Ramsey said the worker made two "forays" to try to control the blaze, one while carrying a fire extinguisher, one while using equipment from a fire backpack in his truck.

The worker then heard someone on the radio answering his earlier call. He got back on the radio, which led to an emergency call being made to Cal Fire. Ramsey said Cal Fire got the alert from PG&E two minutes after a team of firefighters driving up Highway 70, across the river from the blaze, reported it.

According to Cal Fire dispatch audio, the passing firefighters estimated the blaze was about 40 feet by 40 feet.

In comments made during media briefings Wednesday, PG&E CEO Patti Poppe said the worker "alone, by himself, in the wilderness, made multiple trips ... from the top of the slope, where his truck was, down to the source of the fire, attempting to put it out. His efforts can be called nothing less than heroic."

PG&E declined to respond to detailed questions about the timeline of its response, including what time its worker first reached Cresta Dam to look for trouble and what delays he encountered along the road.

Once the fire was reported, Cal Fire dispatched a pair of air tankers and a water-dropping helicopter to hold the fire in check as ground crews tried to reach the incident. But getting to the scene proved as daunting for those crews as it had for the PG&E worker.

A Cal Fire engine and a bus carrying a 20-member hand crew made their way up Camp Creek Road only to find the out-of-service bridge. The hand crew arrived at the bridge after 8 p.m. and still faced a hike of two miles to get to the fire.

The Cal Fire air tankers succeeded in painting a box of retardant around the fire, limiting its spread, and the helicopter took advantage of ready access to the Feather River to make drop after drop on the fire.

Ramsey said that effort was on the verge of success when a drone appeared over the blaze. That led Cal Fire to prematurely end air operations.

Ramsey said drone interference cost about 45 minutes in firefighting time, which he said played a major part in the blaze burning out of control after darkness fell.

At that point, Cal Fire estimated the fire was just one to two acres and spreading slowly. But with no nighttime air support and ground crews continuing to get into the area, the blaze continued to expand, growing to 500 acres overnight.

On Thursday morning, the incident's 10th day, the Dixie Fire had burned 104,000 acres, prompted the deployment of almost 4,000 firefighters and caused the evacuation of thousands of Butte and Plumas County residents. Firefighting agencies report the blaze is 17% contained.