LOS ANGELES (CBSLA.com) — Four members of a family living in a South LA commercial building were treated for smoke inhalation after a fire broke out Wednesday evening.

KCAL 9’s Laurie Perez reported that the raging fire started at the building in the 6000 block of South Broadway, which houses an upholstery business, just before 6:30 p.m. Wednesday.

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“I really can’t know what happened right now,” said a man carrying one of two children who were among the injured. The man seemed too stunned to talk as EMTs whisked him, the children and a woman to the hospital

Los Angeles firefighters said the family was trapped inside the building by security bars on windows and a fence in back.

Fire Chief Don Frazeur said crews had a tough time getting to the fire.

“The most challenging parts were the access to the front,” he said. “We have heavy security bars both front and rear. The fact that there’s no access on the side means you have to make an approach from the front and rear.”

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Some 15 companies and 116 firefighters battled the flames — what the Los Angeles Fire Department calls a major response.

Neighbors rushed out of nearby businesses to watch as power lines sparked, and firefighters attacked the two-story structure from every possible direction.

“My grandpa was there too, so he was in the library, so we started yelling him out,” said neighbor Peter Mejia.

“My shop is right there, but the fire was over there and they were trying to keep it from coming this way, but it was really moving down, you know,” said Leon Singleton.

In addition to looking for a cause, Perez reported that the Los Angeles Department of Building and Safety will be trying to determine why the family was living in the commercial building. Neighbors said they have been living there for a number of months.

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LAFD spokesman Brian Humphrey said no firefighters were injured.