Cause of Boyle Heights warehouse fire believed to be testing conducted by solar contractors: Lineage

South Coast Air Quality Management District officials have extended a special Particle Pollution Advisory through 12:30 p.m. Sunday due to a large structure fire in Boyle Heights that continues to affect air quality east of downtown Los Angeles and in parts of the San Gabriel Valley.

A special Particle Pollution Advisory was extended through 12:30 p.m. Sunday as the Boyle Heights structure fire continues to affect air quality.

Regulatory monitors and sensors have detected elevated levels of fine particulate matter, or PM2.5, since Friday night. Air quality conditions have ranged from "Unhealthy for Sensitive Groups" to "Very Unhealthy" on the Air Quality Index in central Los Angeles County, the San Gabriel Valley, the eastern San Fernando Valley and the northwest San Bernardino Valley.

Officials emphasized that the advisory is not a shelter-in-place order. The Los Angeles County Fire Department is leading the response to the fire, and residents are encouraged to follow any recommendations issued by that agency.

Health officials advise that individuals who see or smell smoke should remain indoors with doors and windows closed. Using air conditioning or an air purifier is recommended, while evaporative coolers, or "swamp coolers," and whole-house fans that bring in outside air should be avoided if possible.

People experiencing health effects are urged to contact Los Angeles County public health authorities.

The advisory remains in effect as crews continue to respond to the fire and monitor air quality conditions across the region.

Mayor Karen Bass on Saturday issued a declaration of local emergency to mobilize additional resources for the city in the days ahead to address a large fire at a cold storage facility in Boyle Heights.

"While the LAFD continues making progress, this is a major, multi- jurisdictional incident," Bass said in a statement Saturday afternoon. "I'm issuing an emergency declaration to ensure the city has the resources it needs as this operation continues and to keep the community safe. The city and county have opened spaces for families seeking relief from the smoke, and we will continue working around the clock and doing everything possible to put this fire out completely."

The city opened a 24-hour-a-day smoke relief center at Pecan Recreation Center, located at 145 S. Pecan St., which will serve the community until further notice. Meanwhile, the county opened a smoke respite center at City Terrace Park, located at 1126 N. Hazard Ave.

The emergency declaration does several things, including:

-- Directs the city's Emergency Operations Organization to be immediately activated and to take "such steps as may be necessary or appropriate for the protection of life, health or property."

-- Directs all city departments impacted by this event, and its ongoing effects, to conduct damage assessments and collect any relevant cost estimates.

-- Requests that the governor waive regulations that may hinder response and recovery efforts; that recovery assistance be made available under the California Disaster Assistance Act; and that the state expedite access to state and federal resources and any other appropriate disaster relief programs.

Councilwoman Ysabel Jurado, who represents the 14th Council District, which includes Boyle Heights, said the emergency declaration is crucial because the hazardous go beyond just the fire.

"Residents have lived through days of smoke, shelter-in-place orders, disruptions to daily life, and ongoing questions about what this means for their health and well-being," Jurado said in a statement Saturday. "I will continue pushing every level of government to bring the resources this community needs so that emergency response, air monitoring, hazardous debris removal, environmental remediation, and public health protections move forward with urgency. Boyle Heights deserves clear information, direct support, and full accountability throughout the response, cleanup, and recovery process."

Three days after the fire erupted at the sprawling warehouse, a large column of smoke on Saturday continued to rise into the air above Boyle Heights and drift into areas that are miles away from the scene.

"This is a very unique fire, a very unique challenge for the Los Angeles Fire Department," LAFD Chief Jaime Moore said at a morning news conference. He described the cold storage facility were the fire was smoldering as "like a giant cooler."

The structure has corrugated steel on its exterior walls, filled with "very, very dense foam," Moore said, adding that ammonia was used as a refrigerant to keep the 85 million pounds of frozen food inside the building cold. "So if you can imagine walking into a cold-storage freezer, that's really what we're dealing with here."

Helicopters have been performing water drops on the building as the foam continues to burn.

A flare-up at the Boyle Heights warehouse sent black and white smoke billowing into the air.

"We've already mitigated the hazardous materials portion but now we're starting to deal with the biohazard portion," the fire chief said, referring to the spoiling food.

He urged anyone participating in outdoor activities on Saturday, including the region's many events connected to the World Cup tournament, to be cautious if they are sensitive to smoke.

"But there's nothing in the air that is so dangerous that we have to do evacuations or even shelter-in-place," Moore said.

Nonetheless, two shelter locations were opened to support anyone affected by the fire: Pecan Rec Center at 145 S. Pecan St., and City Terrace Park at 1126 N. Hazard Ave.

"The good news is, all of our air monitoring that has been done by our department, Hazmat, LA County Hazmat, as well as AQMD, has shown that there are no additional toxic chemicals or hazards within that smoke other than normal structure fire smoke," LAFD Capt. Branden Silverman said earlier. "That said, no smoke is good smoke. We know that people are being affected by this in our city as well as LA County's jurisdiction, and we do want you to take precautions to avoid that smoke whenever possible."

Lineage, the company which owns the facility in Boyle Heights, released a statement saying that it believes the fire was sparked by contractors working on solar panels on top of the roof.

"At this time, we believe the fire began while testing was being conducted by contractors of the third-party owner of the solar array located on the facility's roof," the statement said.

The company said it is assisting the LAFD and other agencies.