According to the letter, a PG&E employee spotted a fire that was close to a power transmission tower around 6:30 a.m. on Nov. 8. Later that day, an aerial patrol realized the tower was damaged as a suspension insulator, which was supposed to support a transposition jumper, had separated from an arm on the tower but was still above the ground.
PG&E said the damaged tower was inaccessible due to the restriction from Cal Fire until Nov. 14 when the company was asked to assist an investigation carried out by Cal Fire. They found a broken C-hook attached to the separated suspension insulator. The C-hook was used to connect the suspension insulator to a tower arm.
Close to where the damage happened and the suspending transposition jumper, a flash mark was observed on the tower by PG&E. In addition, another adjacent power transmission tower was also found damaged, which had an insulator hold down anchor disconnected.
The company also noticed that there were wires down and poles damaged on the road within the burned area. One PG&E employee also observed “several snapped trees, with some on top of the downed wires.”
“These incidents remain under investigation and this information is preliminary,” said PG&E Regulatory Executive Meredith E. Allen. “The cause of these incidents has not been determined and may not be fully understood until additional information becomes available, including information that can only be obtained through examination and testing of the equipment retained by CAL FIRE.”
Last week, a lawsuit against PG&E was filed by a collation of law firms named Northern California Fire Lawyers on behalf of 34 Camp Fire survivors, alleging that the mechanical failure of a component on a power transmission tower resulting from poor maintenance was the cause of the Camp Fire.
The lawsuit claims a steel wire hook on a power transmission tower failed to hold up a high voltage line amidst strong winds and led the uninsulated wire to make contact with the steel tower. As a result, “blazing hot molten materials” fell on dry vegetation below the tower and ignited the fire.