Los Angeles building inspectors have launched an investigation into alleged unpermitted construction at a warehouse that erupted in flames last week causing a health hazard emergency, city records show.

The city's Department of Building and Safety opened the probe on June 17, the same day a fire tore through dozens of solar panels on the roof of the 500,000-square-foot cold storage warehouse in Boyle Heights. 

The stubborn blaze took eight days to extinguish and prompted a shelter-in-place order and state of emergency declaration by Gov. Gavin Newsom.

Concerns first surfaced about the safety of the solar panels following an August 2024 fire on the same roof, which was quickly extinguished by firefighters at the time, a source close to the Los Angeles Fire Department told CBS News.

The earlier blaze cost the logistics company running the warehouse, Lineage, around $6 million, its chief financial officer Robert Crisci revealed in a November 2024 earnings call.

Despite the damage in the 2024 fire, a review of city records showed no record of Lineage or other companies involved obtaining permits for repairs after that fire. There are also no records of building inspections of the roof from 2024 onwards.

"When this new fire happened, people who had done that inspection felt it was déjà vu," said the  source briefed on the investigation of the 2024 fire. The source asked not to be named as they were not authorized to speak publicly. "It seems like the initial fire lessons were never learned."

City records indicated Thursday that a claim of "construction done without permits or inspections" at the warehouse is "under investigation."

In a statement, Lineage said they "believe the fire started on the roof when the owner of the solar array, Altus Power, was doing tests."

Responding to CBS News' questions, a Lineage spokesperson said Altus is "the owner of the array that is responsible for its design, installation, operation, maintenance, and repair."

When asked whether permits were required or obtained for the 2024 repairs, Altus spokesperson Jenny Volanakis said: "Due to the ongoing nature of this matter, including potential litigation, we are unable to comment on it at this time."

CBS News contacted the Los Angeles Department of Building and Safety for comment.

Altus released a statement on Tuesday saying the cause of the fire last week has "yet to be determined".

"Our first concern is for the residents of Boyle Heights, everyone affected by this fire, and for the firefighters working to contain it," the statement said, adding, "We are cooperating fully with the authorities as they investigate."

On Monday, Lineage told CBS LA that the building is owned by Chill Build Los Angeles I, LLC, and that the solar array on the building is owned by Los Palos Street Operating, LLC, a subsidiary of Altus Power. The building's solar contractor is Pearce, which is a subsidiary of CBRE.

The city issued the Chill Build owner a permit to add a "rooftop PV solar system" to the building in July 2020, records show.

The source familiar with the 2024 fire probe said city inspectors now have questions following this new blaze about how the company handled the recovery from the last incident.

Lineage, which describes itself as the world's largest owner of cold storage facilities, experienced a fire at another of its warehouses, in Finley, Washington, which ripped through the entire building and burned for two months in 2024.

Local residents there have since reported emphysema, pneumonia, bronchitis and sinus infections following the incident, and believe smoke from the fire is the cause, according to a report by Northwest Public Broadcasting.

Attorney Will Sykes, who is representing residents suing Lineage over that fire, says the California warehouse raises more questions. 

"It warrants a thorough investigation to see why there were two fires on the same roof over a two-year period," Sykes told CBS News.

Lineage said in a statement to the Los Angeles Times that the "health and safety of our employees and the communities we serve is our top priority," and that its "incident rate" of workplace injury and illness is 14% lower than the industry average.

LAFD Capt. Anthony Tubbs told CBS News the fire in Boyle Heights is now under control, after a week of battling the blaze.

"Our hope is finally, by the end of this week, to turn over to the tenant," he said. "Right now, we are on track to do just that."

Lineage said dangerous chemicals such as ammonia have been transported away from the site as a precaution. Ammonia was used in the site's refrigeration systems.

The fire and resultant smoke that drifted across the city prompted Newsom and Los Angeles Mayor Karen Bass to declare a state of emergency in the Boyle Heights neighborhood on Saturday, unlocking state resources to tackle it.

In a notice on Tuesday, fire officials said that "smoke conditions have improved significantly, and the surrounding community should notice better air quality as firefighting operations continue."

Pearce, the solar contractor, told the LA Times four of its staff were on-site the day the fire started last week.

The California Division of Occupational Safety and Health says it is inspecting both Lineage and Pearce in connection with the fire.