The power line believed to have sparked the Sesnon fire was not covered by strict state inspection and brush clearance rules because it was owned by a private utility on private land, according to regulators.
The California Public Utilities Commission confirmed Thursday that the electrical distribution line is owned by the Southern California Gas Co. and fell onto the utility's property.
Commission rules require power lines owned by electric utilities to be inspected regularly and to have brush under the lines cleared. But PUC spokesman Tom Hall told The Times that the rules don't extend to nonelectric utilities on private land.
"This line does not fall under PUC jurisdiction," Hall said. "But we do have a PUC inspector working with [the Gas Co.] to determine the cause."
Heavy winds blew down the distribution line in a remote unincorporated area of L.A. County north of Porter Ranch, fire officials said, sparking a huge blaze that destroyed 15 homes and damaged six, destroyed 47 outbuildings and may have contributed to the death of a motorist driving on the 118 Freeway.
"It's between the PUC and electric utility companies. We're not even looking at that," said Steve Dunn, senior civil engineer with the county Department of Public Works' utility section. "It's my understanding there's a maintenance program that's developed by electric utility companies in compliance with the CPUC."
It remains unclear whether the power line that fell had been inspected or whether the brush below had been cleared. A spokesman for Southern California Gas said the utility was fully cooperating with the investigation but declined to answer more detailed questions.
Los Angeles County Fire Deputy Chief Scott Poster, whose agency oversees brush clearance in unincorporated areas, said there are no county regulations specifically requiring brush removal under electrical lines on private property unless the lines are near a structure.
There has been growing concern about the danger posed by power lines during the fire-prone Santa Ana winds season.
Power lines were the suspected culprit behind at least five of the fires that burned across Southern California last October, including one in San Diego that consumed 200,000 acres, destroyed 1,041 homes and killed two people.
But placing lines underground is highly expensive -- with some cost estimates as high as $1 million a mile.
The utilities commission investigated last year's Witch fire in San Diego and concluded in a report released last month that San Diego Gas & Electric Co. failed to properly maintain power lines that were felled by the wind (the utility strongly disputed the finding).
The commission and fire authorities are just now beginning their probe into the cause of the Sesnon fire, which began Monday. Los Angeles County Fire Department officials said they had tracked the start of the blaze to an area near Palo Solo Mountainway, west of Limekiln Canyon Road.
Southern California Gas spokeswoman Denise King said the utility does have power distribution lines around the hilly region to serve offices and equipment for a natural gas storage facility in the area. Citing the ongoing investigation, she declined to speak about the specific line that fell.
From that location, the Sesnon fire pushed rapidly southwest, eventually jumping the 118 and going into Chatsworth and eventually toward Simi Valley.
The blaze had burned 14,000 acres and was 70% contained as of Thursday night.
Fire officials said they expected full containment by Saturday. (The Marek fire, which burned 41 dwellings in and around Lake View Terrace, was declared 100% contained Thursday).
L.A. County officials said they asked the utilities commission to study the issue of brush fires sparked by power lines after blazes last year in Malibu and Santa Clarita.
Dunn said officials have been told the commission has not yet completed the report.
Bruce McClendon, director of the county's Regional Planning Department, said he'd like to see more analysis of the issue so officials can improve development standards in high fire-risk areas, possibly including special rules for power lines.