Smoke concerns grow in L.A. as warehouse fire burns for 4th straight day

Firefighters were facing renewed challenges Saturday at a large cold storage warehouse fire in the Boyle Heights neighborhood of Los Angeles, where officials say conditions inside the structure remain highly complex. At a Saturday morning briefing, L.A. Fire Department officials described the facility as a 500,000-square-foot commercial building, which is used to store frozen foods. "The best way to describe this is like a giant cooler," said L.A. Fire Chief Jamie Moore, who added that the structure was built with corrugated steel walls filled with dense foam insulation and reinforced interior steel panels. The building also used ammonia as part of its refrigeration system to maintain extremely low temperatures for frozen food storage. Moore said the nature of the materials inside has made the fire difficult to control, as the foam insulation continues to burn slowly once ignited. Crews have relied on continuous helicopter water drops since the start of the incident to keep the structure cooled and prevent further escalation. Officials have also used large aerial ladder pipes, directing thousands of gallons of water per minute onto the building to contain the blaze. 85 million pounds of frozen food complicate firefighting efforts With an estimated 85 million pounds of frozen food still inside the facility, firefighters say access is extremely limited due to zero visibility and unstable interior conditions. …