Grid infrastructureUnited StatesEIR-1563

Transformer failure at SCE substation disrupts power in the Downey and Norwalk area

Dec 2024Published 29 Sept 2026Responsible editor: Chief Editor

SignificantElectricalProvisional

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Companies named in the reporting of this entry (being named is not a finding of fault): Southern California Edison

What happened

A transformer failure at a Southern California Edison substation in the Downey/Norwalk area of California caused a widespread power outage on 24 December 2024. Southern California Edison said the outage began around 1:30 p.m. and affected more than 31,000 customers. Power was restored to most customers the same day, and all affected areas in Downey were reported restored the following morning. Metro C Line trains were halted between Norwalk and Willowbrook/Rosa Parks stations, with buses used as a replacement.

Traffic lights were reported out at multiple intersections and some shops closed. There were also reports of power loss in Santa Fe Springs, Bellflower, Whittier, Compton, Lakewood, Paramount and South Gate, though how far the outage spread was not confirmed. The utility outage map listed storm conditions as the cause of the Downey outages.

Contributing factors

A transformer failure was reported by the utility. Storm conditions were listed as the cause on the utility outage map. No further cause has been reported.

Lessons learned

Grid operators should check substation redundancy and the ability to re-route supply quickly ahead of forecast weather.
Early coordination with transport agencies limits disruption when a substation fault affects traction power.
Clear public updates on restoration times help customers plan during holiday periods.

More lessons on weather and external hazards, outages, backup supply and restoration, from every incident on the register.

Source

abc7.com

Other entries that name Norwalk

Substation fire in Norwalk cuts power to thousands of Eversource customers EIR-1160 · 2020
Underground transformer explosion closes street in Norwalk EIR-1249 · 2020

Published 2026-09-29. Written from public reporting. Descriptive, not investigative. See the data accuracy disclaimer.

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