HOLLYWOOD (CBSLA.com) — Crews battled a major emergency structure fire Tuesday morning in Hollywood.

The fire was reported just around 7 a.m. at a two-story mixed-use commercial building in the 5400 block of Santa Monica Boulevard, the Los Angeles Fire Department said.

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When firefighters arrived on scene, they found heavy smoke coming from the attic of the pre-1930s brick structure.

According to the LAFD, the fire started in the building’s attic or electrical room overnight.

“For an attic fire to blossom up with such intensity, it usually tells us it had been smoldering for some time,” Deputy Chief Joseph Castro said.

During the fight, more than 150 firefighters from 34 companies were forced to evacuate the structure due to dangerous conditions and battled the flames from the exterior.

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Firefighters were later able to re-enter the building and the fire was declared a knockdown at 8:58 a.m., officials said.

Traffic was completely shut down near the area, however, and for several blocks businesses weren’t able to accommodate their customers.

Maria Ruiz said she lost about $500 in revenue at her store by mid-day.

“Because we are in front of the bus stop, we lost a lot,” Ruiz said.

It was unclear what ignited the fire. Officials say the building is likely a total loss.

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No injuries were reported.