Updates on key issues surrounding the fires.

cause of the fires

The California Department of Forestry and Fire Protection, Cal Fire, has not yet named a cause for any of the October fires. The California Public Utilities Commission is looking into whether Pacific Gas and Electric Co.’s field equipment — power lines, poles, transformers and other gear — may have played a role in the blazes.

About 150 lawsuits have been filed blaming PG&E for the flames, including suits by Sonoma, napa and mendocino counties. PG&E has suggested that the massive Tubbs Fire may have been started by another party’s power line on private property near Calistoga. So far, no evidence has surfaced in public indicating that arson or out-of-control campfires started the blazes. — David R. Baker

Emergency alerts

State officials found that Sonoma County emergency managers were not prepared to properly warn residents, leaving many in the dark about imminent fire danger. The county declined to send a Wireless Emergency Alert to cell phones in the region, fearing creating a panic.

In the months since, the Federal Communications Commission has adopted long-stalled upgrades to the WEA system that should boost the alerts’ effectiveness and allow agencies to better target specific areas. Several north Bay lawmakers have introduced a bill requiring all counties in the state to create uniform emergency notification protocols and develop guidelines for using WEAs. — Joaquin Palomino

Mutual aid

After the fires broke out, commanders in north Bay counties requested help from nearby fire departments through the state’s mutual aid system, which is critical in large-scale disasters. Those calls went largely unanswered, underlining long-held concerns by fire officials around the state about growing strains on the mutual aid system. California fire officials have asked for $100 million to improve the system. — Joaquin Palomino

Regulatory changes

Since the fires, the California Public Utilities Commission has approved tougher fire safety rules for electric utilities. The rules, which had been in development for nearly a decade, require the companies to keep tree branches trimmed farther back from power lines and to prioritize repair work in high-risk areas.

The commission has yet to settle the question of whether utilities can be held liable for wildfire damage even if they have followed all state safety rules to the letter. PG&E and the state’s other utilities are lobbying in Sacramento to be exempted from “inverse condemnation” liability. — David R. Baker

Actions by PG&E

In response to the fires, PG&E launched its largest disaster-response operation since the 1989 Loma Prieta earthquake, mobilizing 4,300 workers to restore electricity and natural gas service. The company has spent $219 million replacing more than 160 miles of power lines and 2,800 poles.

PG&E also has taken preemptive steps to help prevent future wildfires. The utility says it will turn off power lines at times of extreme fire danger and will change the way it uses automated devices called reclosers that try to restart power lines that have unexpectedly switched off. At times of high fire threat, it will reprogram reclosers to avoid sending electricity through a downed line. It also plans to replace many wooden poles in high-risk areas with steel poles.

In addition, PG&E is creating a Wildfire Safety Operations Center in San Francisco to monitor the weather for conditions that could start fires and coordinating its response when a fire erupts. PG&E also will add several hundred weather stations to its existing network of 100 and will contract with private firefighting services to provide emergency aid. — David R. Baker

claims for losses

Homeowners and renters in Sonoma County have filed 14,692 residential insurance claims totaling $6.9 billion. Of those, 4,821 claims were for total losses, according to the California Department of Insurance. In addition, insurers received 1,772 commercial property claims totaling $781 million. Of those, 153 were for total losses. Total insured losses, including residential, commercial, auto and other lines, amounted to nearly $8 billion in Sonoma County. — Kathleen Pender