BREA (CBSLA) — Approximately 15,000 people were without power in Placentia, Fullerton and Brea — including shoppers at Brea Mall — following a transformer fire Tuesday.

Brea Fire responded to the fire at Imperial Highway at Associated Road that caused the outage over the area, including the Brea Civic Center, at approximate 5:15 p.m.

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Things got tense inside the Brea Mall for holiday shoppers who were stopped in their tracks when the shopping center went dark.

“It was scary because it just went dark,” one woman said.

“I was scared, like, because, like, maybe there was a shooting, ya know,” her daughter added. “It could be anything.”

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Hundreds inside the mall grabbed their cell phones, turning on their flashlights so they could see.

“No one was screaming or anything. Everyone was really calm and they just escorted people out of the mall,” another woman said.

Power was restored in most areas by 6:30 p.m., according to the city’s Emergency Preparedness Program.

Motorists were advised to drive cautiously and treat intersections where lights are out as a four-way stop as signal maintenance was ongoing.

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A spokesperson for Southern California Edison told CBS2/KCAL9 crews were still working to determine what triggered the fire, which they say occurred at one substation.