With power returned to most of the hundreds of thousands that were in the dark due to wildfires in southern California and related Public Safety Power Shutoff (PSPS) events, investigators are now trying to determine the causes of the huge fires that have killed at least 24 people and destroyed thousands of homes and businesses in the Los Angeles area.
Lightning, the most common source of fires in the U.S. according to the National Fire Protection Association, was quickly ruled out as a cause. There were no reports of lightning in the Palisades area or the terrain around the Eaton Fire, which started in east Los Angeles County and has also destroyed hundreds of homes.
The next two most common causes: fires intentionally set, and those sparked by utility lines. So far there has been no official indication of arson in either blaze, and utility lines have not yet been identified as a cause either. Utilities are required to report to the California Public Utilities Commission when they know of “electric incidents potentially associated with a wildfire.” CPUC staff then investigate to see if there were violations of state law.
SCE weighs in
The 2017 Thomas Fire, one of the largest fires in state history, was sparked by Southern California Edison (SCE) power lines that came into contact during high wind, investigators determined. The blaze killed two people and charred more than 440 square miles (1,140 square kilometers).
SCE filed two Electric Safety Incident Reports (ESIR) related to current wildfires, one for the Eaton Fire and another for the Hurst Fire. ESIRs are filed with the California Public Utilities Commission (CPUC) for incidents that meet certain criteria, such as significant media attention or a governmental investigation. These brief reports contain preliminary information and are provided within two to four hours after a triggering event. To comply with CPUC requirements, these reports are often submitted before SCE can determine whether its electric facilities are associated with an ignition.
On Friday, SCE filed a report with the CPUC related to the Eaton Fire in the hills near Pasadena, an area the utility serves. Edison said it has not received any suggestions that its equipment was involved in the ignition of that fire, but that it filed the report with state utilities regulators out of “an abundance of caution” after receiving evidence preservation notices from insurance company lawyers. SCE said it conducted preliminary analysis of electrical circuit information for the four energized transmission lines in the Eaton Canyon area, which showed no interruptions or operational/electrical anomalies in the 12 hours prior to the fire’s reported start time until more than one hour after the reported start time of the fire.
The next day, SCE filed another report related to the Hurst Fire once SCE learned fire agencies are investigating whether SCE equipment was involved in the ignition, which is a triggering event for reporting. SCE noted that the fire was reported at approximately 10:10 p.m. on Jan. 7, and preliminary information reflects the Eagle Rock – Sylmar 220 kV circuit experienced a relay at 10:11 p.m. A downed powerline was discovered at a tower associated with the Eagle Rock – Sylmar 220 kV circuit. SCE said it does not know whether the damage observed occurred before or after the start of the fire.
How many outages remain?
While the vast majority of electric customers in southern California have had their power restored since last week, roughly 56,000 are still without power statewide as of Monday morning, according to poweroutage.us. SCE customers account for roughly 34,000 of those outages, with Los Angeles Department of Water & Power customers accounting for another 16,000.
SCE said it has restored power for more than 500,000 customers since January 7, but noted that “severe equipment damage” and access restrictions caused by the wildfires may lead to restoration times of up to several weeks for the remaining outages. Additionally, although wind conditions have improved, “dangerous” weather is expected to continue until at least the 15th in some areas, and some customers may still be de-energized as part of a PSPS throughout the week, SCE said.
LADWP said on Sunday that it had restored power to more than 360,000 customers since the start of the windstorm that led to the wildfires, and added that its crews were assessing the fire-affected areas and will begin restoration efforts when those assessments are complete.
This article contains reporting from the Associated Press.
