"Fire companies went in. They did an aggressive attack on the fire. They had a lot of storage of tires inside, petroleum products -- not only tires inside, but on the roof as well," said L.A. City Fire Captain Jaime Moore.
A front gate to the property was locked. When firefighters arrived on the scene, they found six people locked in who were trying to get out. They were eventually saved, but two people inside the building were not.
Fire crews discovered two bodies on the second floor of the Gomez Tire and Muffler shop, but the gender and ages of the victims were not released.
Crews continued to search the building to look for more victims because there were reports of people living inside the building.
Authorities said two men were injured. A 61-year-old man who was trying to put out the fire with a hose suffered burns on 40 percent of his body, and a 33-year-old man was burned on his arms and back. Both victims were transported to USC Medical Center.
"This individual was trying to extinguish the fire with a garden hose and did not dial 911 immediately which caused a delay in the emergency response, thus the fire was as large as it was," said Moore.
Tires stored on the roof of the building caught fire, sending a thick plume of black smoke through the neighborhood.
Los Angeles County fire inspector Don Kunitomi said tire fires are problematic because a main ingredient in making a tire is highly flammable petroleum.
The 100-foot-by-100-foot building was more than a tire and muffler shop.
Ramon Montes Hernandez said he was one of 11 people living there. He had left for work just before the fire broke out, and he's concerned that his cousin did not make it out.
"Obviously he's very distraught, he's saying his chief concern is he wants to know whether or not his cousin was in fact one of the fatalities so that he can let his wife know in Mexico, and let her know under which circumstances he passed away," said Los Angeles City Councilman Jose Huizar.
"If you look at this building, it doesn't look like it's zoned for residential, so we have to determine exactly why individuals were allowed to live here, and we want to remind the public that they should not live in dangerous conditions in areas that are not zoned for residential use," said Huizar. "It's dangerous to themselves and it's also dangerous to the local community."
Arson investigators were at the scene all day Monday.
The cause of the fire was not determined. It was categorized as a "fatality-fire investigation."
City News Service contributed to this report.