Residents near the burning cold storage warehouse in Boyle Heights were again ordered to stay indoors as the facility continued to smolder, prompting an ongoing air quality advisory through Friday.
Jesus Delgado, who lives just yards from the burning site, said the smell in the area has been overwhelming.
Los Angeles Fire Department Chief Jaime Moore said investigators are looking into the expansive array of solar panels covering the facility's roof as they work to find out what started the massive blaze.
"It smells like burned rubber," he said.
Delgado and his grandmother evacuated during the height of the fire as crews made more than 30 water drops to control the blaze. When he returned Thursday, he found the fire extinguished but the building still being ventilated, and authorities had issued a new shelter-in-place order due to the smoky conditions.
"It will cause a lot of headaches for those that have trouble, like say that they're sick or something ... it will really affect them a lot," Delgado said.
Despite the lingering odor, Los Angeles Fire Department Chief Jaime Moore said monitoring has not detected dangerous conditions.
"We're getting absolutely no readings of any concern," he said.
The facility, operated by a company called Lineage, is used to store food and beverages and utilizes a process known as "blast freezing," according to its website.
Moore said the fire appears to have started in an expansive array of solar panels covering the facility's roof.
"This a huge field of solar panels. This entire roof is covered with solar panels, so obviously there's some sort of concern there with the way it was built, and that's something they're going to be looking at and trying to investigate," Moore said.
Authorities said they continue to monitor conditions as the investigation into the cause of the fire moves forward.