PARADISE — Downed PG&E power lines, amid high winds, may have sparked the deadly Camp Fire that has destroyed the town of Paradise and killed at least five people, according to firefighter radio transmissions reviewed by Bay Area News Group.

At about 6:33 a.m. Thursday, firefighters were dispatched to a vegetation fire “under the high tension power lines” across the Feather River from Poe Dam, where Cal Fire officials have pinpointed the fire’s origin on the agency’s incident page, according to hours of radio transmissions reviewed by this news organization. The first fighters arrived there at 6:43 a.m and noted the fire was being buttressed by 35 mph winds.

“We’ve got eyes on the vegetation fire. It’s going to be very difficult to access, Camp Creek Road is nearly inaccessible,” one firefighter told dispatch. “It is on the west side of the river underneath the transmission lines.”

The utility, which has already been criticized and sued in a number of other large and deadly fires across California, had announced beginning Tuesday that it might shut down power to the impacted parts of Butte County amid forecasts of high wind and low humidity. But it never did.

Butte County District Attorney Mike Ramsey said Friday that his office has been in discussions with Cal Fire to preserve the fire scene and any potential evidence for a possible criminal investigation.

Ramsey said he had no information that the Camp Fire was intentionally caused. He also said it was too early to know whether the cause of the fire could have been negligent in nature.

Cal Fire, Ramsey said, will investigate and determine the cause of the fire. Should a criminal case arise from the investigation, the District Attorney’s Office would be the prosecuting agency. The district attorney said it was not unusual for his office to become involved in fire investigations where there is loss of life.

Cal Fire spokesman Scott McLean emphasized the cause is still under investigation, but added that probe would include “electrical equipment.”

PG&E spokesman Jason King said no cause of the fire had been determined.

“We can’t speculate on the cause of the fire, there will be an investigation,” he said.

After the first radio call, an immediate, multi-alarm response was sent to the area by Pulga and Camp Creek roads, near the dam which is popular with kayakers and one of PG&E’s 10 hydroelectric stations along the north fork of the river. Google satellite images show PG&E transmission lines above Pulga and Camp Creek roads.

“The (reporting party) is calling from Poe Dam looking across under the high tension power lines. There’s a possible power line hazard,” a dispatcher alerted responding crews, including six engines and a number of more personnel.

At 6:34 a.m. and about eight miles west, another fire crew was dispatched to a report of a branch taking down residential power lines in the neighboring town of Magalia. During last year’s Sonoma and Napa county fires, within the first 90 minutes of the fires’ origin, Sonoma County dispatchers sent fire crews to at least 10 different locations for downed wires and problems with the electrical system amid high winds.

As firefighters rushed to the Poe Dam fire early Thursday morning, each truck acknowledged over the radio “Copy, power lines down,” as part of safety protocol for firefighters.

The first firefighter at the scene quickly recognized the seriousness of the situation and called for an additional 15 engines, four bulldozers, two water tenders and four strike teams and hand crews.

“This has got the potential for a major incident,” he told dispatch, alerting them to evacuate Pulga, the town immediately southwest, and to find air support.

On Tuesday night, PG&E first tweeted that power might be shut down to certain counties, including Butte County and about 26,500 customers in cities and towns including Berry Creek, Forest Ranch, Magalia and Paradise.

POTENTIAL OUTAGE PREPARATION: PG&E urges customers to prepare for possible proactive power shutoff (11/8) and extended outages in portions of the following counties: Lake, Napa, Sonoma, Butte, Plumas, Yuba, Sierra, Placer & Nevada. Learn more and prepare: https://t.co/tNuuZUVnRv — PG&E (@PGE4Me) November 7, 2018

Over the next 48 hours, the utility tweeted out 17 different warnings of an impending Thursday morning shut-off. It even tweeted out a warning at 7:56 a.m. Thursday, more than an hour after the fire was reported under one of its downed power lines, that the shut-off was still an option.

ADVISORY FOR THURSDAY (11/8): Due to evolving weather & potential extreme fire danger, PG&E may proactively shutoff power for safety to some customers in parts of (counties): Lake, Napa, Butte, Plumas, Yuba, Sierra, Placer and Nevada. Learn more: https://t.co/OkH27t2G52 — PG&E (@PGE4Me) November 8, 2018

PG&E released a statement Thursday afternoon, almost nine hours after the Camp Fire first sparked, calling off the shut down “as weather conditions did not warrant this safety measure.”

“We want to thank our customers for their understanding and for their actions in preparation of a possible Public Safety Power Shutoff,” Pat Hogan, PG&E senior vice president of Electric Operations, said in the statement.” We know how much our customers rely on electric service, and we will only consider temporarily turning off power in the interest of safety and as a last resort during extreme weather conditions to reduce the risk of wildfire.”

PG&E has determined that it will not proceed with plans today for a Public Safety Power Shutoff in portions of 8 Northern CA counties, as weather conditions did not warrant this safety measure. We want to thank our customers for their understanding. https://t.co/DqYJz1iWve pic.twitter.com/fIjiExGmFP — PG&E (@PGE4Me) November 8, 2018

On Friday, King declined to get into specifics about why PG&E called off the shut down, saying only: “We chose not to implement the public safety power shut off in any location.”

In its warnings, PG&E had warned of sustained winds of 20 to 30 miles per hour, with gusts of 40 to 50 mph forecasted overnight Wednesday into Thursday, lasting until late afternoon.

When implementing a Public Safety Power Shutoff the utility factors in strong winds, very low humidity, critically dry vegetation and on-the-ground observations.

PG&E’s stock plunged Friday by almost $8 a share, a more than 16 percent drop amid the fires blazing across the state. The decline wiped out PG&E’s entire gains for the year and was the biggest one-day decline for the stock since 2002.