BOYLE HEIGHTS (CNS) - As smoke continued billowing from the smoldering Lineage cold-storage warehouse in Boyle Heights, degrading air quality in the area, fire crews worked again Tuesday to fully douse pockets of fire inside the massive structure, with the goal of completing the work by week's end.

Los Angeles Fire Department Chief Jaime Moore told reporters Monday he is hoping to have the fire extinguished and to be able to turn control of the warehouse back to Lineage by Friday.

"I know it's very ambitious, considering what's happened in the past, but that's what my goal is and that's what we're working towards," Moore said.

Lineage Logistics officials issued a statement Monday evening saying the company was "grateful and encouraged by the news from the Los Angeles Fire Department that, while things can always change, they are looking to extinguish the fire in days and turn over the building to the owner and our company for clean up as early as Friday."

"The bravery and expertise we have seen from the firefighters of the LAFD is nothing less than extraordinary.

"As we remain committed to doing everything we can to help firefighters and the community, we want to be clear that this fire was not caused by our operations or our team. Lineage is the tenant-operator of the building, not the owner.

"We believe the fire started on the roof when the owner of the solar array, Altus Power, was doing tests. The solar array does not power the building directly but provides power into the city power grid. As we step up for the community, we are also urging Altus to join us getting the Boyle Heights community the support they desperately need."

Altus issued a statement insisting that the cause of the fire remains under investigation.

"Our first concern is for the residents of Boyle Heights, everyone affected by this fire, and for the firefighters working to contain it," according to the company. "The cause of the fire where our rooftop solar array is located at the Los Palos Street facility has yet to be determined. We are cooperating fully with the authorities as they investigate."

LAFD officials said crews made significant progress Monday on the blaze at roughly 491,000-square-foot warehouse at 1400 S. Los Palos St., near the Indiana Street off-ramp of the Santa Ana (5) Freeway. Crews have been tearing down walls of the building to give firefighters better access to pockets of fire smoldering deep within the structure.

Smoke conditions improved since Sunday and were expected to continue improving as operations move forward, according to a statement from the department issued at 8 p.m. Monday.

"LAFD is working with allied agencies, contractors, and industry experts while utilizing specialized tools and tactics used at large industrial and oil rig fires," the statement said. "Heavy equipment operators are using long-reach excavators and dozers to safely remove debris, expose hidden hot spots, and improve access for suppression efforts."

For firefighter safety, crews remain out of the cold storage areas due to unstable storage racks, a compromised roof, and products that could shift or fall, officials said. Heavy equipment is being used whenever possible to reduce risk while continuing extinguishment operations.

The warehouse erupted in fire about 2:30 p.m. Wednesday, and while crews initially believed they had contained the blaze -- in part through the rare use of water-dropping helicopters on a structure fire -- pockets of fire continued to burn inside the structure.

Moore said fire activity in the structure decreased throughout the day on Monday, as firefighters poured roughly 12,000 gallons of water per minute into the structure, which was storing millions of pounds of food.

As the fire has continued burning, air quality concerns have persisted for large swaths of Los Angeles, but the U.S. Environmental Protection Agency and South Coast Air Quality Management District have not detected anything beyond normal combustible material typical after a fire, authorities said.

A special Particle Pollution Advisory issued by the AQMD was extended until at least 12:30 p.m. Tuesday.

County health officials on Monday urged residents impacted by the smoke to take precautions, such as staying indoors, keeping windows and doors closed, limiting activities outdoors and wearing a high-quality face mask while outside.

County health officer Dr. Muntu Davis said anyone experiencing severe symptoms or worsening conditions should contact their doctor.

"This would include symptoms like difficulty breathing, chest pain, significant breathing distress," Davis said.

He said people should "really pay attention to where you are, what you're seeing and what you're feeling, and how you feel when you're outside."

Mayor Karen Bass and Councilwoman Ysabel Jurado, who represents the 14th Council District, which includes Boyle Heights, said Sunday officials were handing out hundreds of air purifiers and masks. County Supervisory Hilda Solis said the county was also working to distribute purifiers and masks.

Additional resources were being put in place at the warehouse after Gov. Gavin Newsom, Bass and Solis each issued a emergency declarations to support the ongoing fire fight.

"California is deploying specialized resources, supporting local firefighters and pre-positioning critical supplies to protect communities and accelerate recovery," Newsom said in issuing the declaration.

Two shelter locations were opened to support anyone affected by the fire: a city facility at the Pecan Recreation Center and a county location at City Terrace Park. The Weingart East Los Angeles YMCA also opened an emergency shelter at its facility where it is also distributing masks.

The city's local 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 Gov. Gavin Newsom 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.

Solis said the City Terrace Park shelter was providing masks, bottled water, non-perishable food and information from public health and air quality officials. Transportation assistance, including coordinated rides, was also made available to help residents safely access the site, she said.

Information about the shelter, available services or transportation assistance is available at AlertLA.org.