Multiple traffic signals across Arcadia went dark Saturday and the Arcadia Police Department lost its non-emergency and business phone lines after a power outage of unclear cause hit the city, just as tropical moisture from Hurricane Marie soaked the San Gabriel Valley foothills. Officials had not announced when power would be fully restored, and Arcadia's front lobby was closed to the public while crews worked the problem.
The outage forced Arcadia police to lean on neighboring Monrovia for help, according to KTLA, whose reporting from Lily Dallow forms the backbone of what's known about the disruption. The Monrovia Police Department dispatched emergency calls to Arcadia officers and answered Arcadia's emergency lines directly while the outage persisted. Arcadia police stood up a temporary non-emergency number, 626-701-4584, for residents who needed to reach the department without dialing 911 — and 911 itself remained operational throughout, per the same report.
Storm Moisture Meets an Aging Grid
The disruption landed as Hurricane Marie, though staying offshore, pushed rain, gusty winds and dangerous surf into Southern California. Tropical moisture from the storm dropped between 0.25 and 1.0 inches of rain across Los Angeles County on Saturday, with forecasters projecting as much as 1.5 inches in foothill communities near Arcadia, according to the Los Angeles Times. The National Hurricane Center and the National Weather Service also kept ocean safety warnings in place through Tuesday, with the offshore storm generating 6- to 10-foot swells and dangerous rip currents along south-facing beaches.
Despite the stormy conditions, Southern California Edison spokesperson Scott Johnson said the utility had not seen a significant increase in weather-related outages, the KTLA report notes. Edison reported 44 outages across its service territory, which spans more than 50,000 square miles across central and Southern California. The utility also removed Public Safety Power Shutoff warning statuses for Los Angeles, Orange and Ventura counties, leaving just over 1,400 customers remaining in PSPS warning areas and only four customers actually without power due to shutoffs.
Why the Lights Went Dark So Fast
Exactly why Arcadia's signals and police phones lost power hasn't been pinned down, and it remains an open question whether the city's traffic signals lacked battery backup hardware altogether or whether the outage simply outlasted it. Standard lead-acid battery backup systems installed at municipal intersections typically sustain full operations for only four to six hours during a blackout before going dark, according to the County News Center. Monrovia's ability to instantly absorb Arcadia's emergency call routing reflects long-standing mutual aid agreements that San Gabriel Valley cities maintain for exactly this kind of infrastructure failure, per regional safety planning documents.
What Drivers Need to Know at Dark Intersections
Arcadia police urged drivers to use extra caution around any traffic signal that has gone completely dark, telling motorists to treat such intersections as four-way stops. That guidance lines up with California law: under Vehicle Code § 21800(d)(1), motorists approaching an intersection with an inoperative signal are legally required to stop and treat it as a four-way stop before proceeding, according to FindLaw. Drivers should come to a complete stop, yield to other vehicles and pedestrians, and proceed only when it's safe to do so.
The stakes for ignoring that rule aren't small. Citing a violation of CVC § 21800 for failing to yield at a dark signal carries a base fine of $238, with total out-of-pocket court assessments and administrative fees often reaching $490 to $550, per Cron Israels and Stark. Caltrans traffic safety analyses list right-of-way violations and failure to obey traffic control devices among the top six causes of motor vehicle collisions statewide, underscoring why blacked-out intersections pose a real hazard beyond mere inconvenience.
Edison's Broader Storm Posture
Southern California Edison positioned crews and equipment throughout its service area ahead of the weekend's weather and urged residents to prepare for possible outages more broadly. The utility recommended residents keep flashlights, batteries, a first-aid kit, drinking water and fully charged cellphones or portable chargers on hand. Anyone who encounters a downed power line should stay at least 100 feet away and call 911 rather than approach it.
Under California Public Utilities Code § 451 and California Public Utilities Commission guidelines, electric utilities are authorized to execute Public Safety Power Shutoffs as a last resort, but must weigh wildfire prevention against the real public harms of losing grid power, according to the California Public Utilities Commission. That balancing act was on display this weekend as Edison scaled back PSPS warnings even while localized outages, unrelated to any shutoff, still knocked out signals and phone lines in Arcadia.
Arcadia's outage arrives on the heels of Hoodline's earlier holiday-weekend rain warning, which flagged the tropical moisture from Hurricane Marie as a threat to the region well before the storm's remnants reached the foothills. Residents in Arcadia and nearby communities are being told to keep watching for updates on when full power — and full traffic signal function — will return.
