All evacuation orders were lifted with the exception of the area between Kenter Avenue on the west, the 405 Freeway on the east, Mountaingate Avenue on the north and Sunset Boulevard on the south.
The fire, which burned 12 homes Monday, was 27% contained and had scorched 745 acres as of Wednesday morning, officials said.
Firefighters spent the night and morning putting out hot spots and flare-ups.
The fire was sparked by a tree branch that fell on power lines, Los Angeles Mayor Eric Garcetti said Tuesday evening. Video shows the branch breaking off a eucalyptus tree and sparking the fire in the 1900 block of North Sepulveda Boulevard.
The power lines are operated by the L.A. Department of Water and Power, according to a fire official. The agency said it was cooperating with the investigation.
DWP General Manager Marty Adams said the utility had cleared brush along the Sepulveda Pass in July. The DWP also said in a statement that there was “no failure of electrical equipment.”
Under the agreement, PG&E will overhaul its board, and California regulators will gain increased oversight of the utility.
A federal judge wants PG&E to hire 1,100 more tree trimmers to prevent fires from igniting, but the utility’s lawyers said they couldn’t commit to that.
Authorities are unsure what caused the explosion, and are investigating complaints from nearby residents that noxious gases wafted into their neighborhoods.
Unlike Pacific Gas & Electric Co. and Southern California Edison — the state’s largest power providers — the DWP does not shut off service to customers before or during a wind event, in part because the utility covers a more compact, urban area.
“Our systems are completely different,” Andrew Kendall, senior assistant manager of the DWP’s power system, said at a board meeting this month. “We have a 465-square-mile service territory. PG&E’s is 70,000 square miles, Edison is 50,000 square miles.”
Kendall said the DWP is “in an area where we’re no more than a five- to seven-minute LAFD response. So right now, at this time and based on previous history, we don’t feel we’re at a point where it’s prudent to do a shutdown.”