The Los Angeles City Fire Department (LAFD) concluded the investigation into the Los Palos Fire, declaring the exact cause undetermined, but concluded that the origin of the fire was on the roof of Lineage Logistics and an “unknown electrical event” was the most likely cause, according to the investigation report.

The June 17 fire burned for several days, damaging about half of the cold-storage facility and destroying nearly all of its contents, according to the report.

Lineage is facing multiple civil lawsuits from employees and nearby residents and has filed its own lawsuit against Altus Power, its subsidiary Los Palos Street Operating that owns the project, and Pearce Services, who was working on a rooftop solar array when the fire occurred. The lawsuit is seeking more than USD 1bn in damages.

Despite the LAFD ruling the cause of the fire undetermined, a Logistics spokesperson told NPM that the report “validates what we have known all along: This was a solar fire.”

An Altus Power spokesperson provided the following statement to NPM.

“Lineage’s statement is riddled with misinformation in a blatant attempt to deflect blame for their role in this matter, including any damage caused by the release of substances from the warehouse, not the solar panel. We take safety extremely seriously and our strong safety record reflects our rigorous protocols and response procedures, in contrast to Lineage, whose track record is well documented. As tenant-operator that controlled the facility, Lineage is legally responsible for overseeing the site remediation, including cleanup, debris removal, and remediation resources. We will contest the claims in court.”

Pearce Services did not respond to NPM’s request for comment.

LAFD Report

The LAFD reported in its investigation that the fire department was called to the scene on June 17 with reports of a fire on the solar panel-covered roof of the commercial warehouse facility.

The report also highlighted witness interviews, which included a Lineage manager that reported four technicians from Pearce that checked into the building the morning of the fire. The manager later received a call from a Lineage supervisor stating that a Pearce technician had called from the roof to report a fire. That Manager called the technician to confirm before calling 911.

The Lineage manager told LAFD that before exiting the roof, that same technician said, “he was scared when the fire broke out and tried to put it out, but then there were spot fires all around.”

In a separate witness interview, a Lineage supervisor responsible for verifying the operational safety of the solar panels said Pearce had spent months repairing the solar system after a 2024 fire. Lineage required Pearce to follow a commissioning “Playbook,” with the Lineage supervisor responsible for quality-assurance checks. Because testing was not scheduled until the week of June 22, no safety tests had been completed, and the system was not supposed to be supplying the grid.

The supervisor said that Lineage lacked SCADA (Supervisory Control and Data Acquisition) access and could not verify compliance, leaving open the possibility that Pearce sent power to the grid before commissioning.

A Pearce Services Health, Safety and Environment employee spoke to LAFD on behalf of a technician on site when the fire broke out who said they saw smoke coming from a grid while working. The Pearce employee observed fire coming from underneath a panel and observed one panel had melted. The employee used a fire extinguisher in an attempt to extinguish the fire and observed additional fires spotting in close proximity.

The solar facility consisted of 12,400 solar panels.

Earlier this week, Los Angeles City Council voted to withhold warehouse reconstruction permits.