Firefighters continue battling a large cold-storage warehouse fire in Boyle Heights, Los Angeles, for a fourth straight day. Multiple reports say conditions at the scene remain highly complex, with ongoing challenges for response teams. Officials also note that smoke concerns are increasing as the fire continues to burn. In response to the incident and to support emergency efforts, Mayor Karen Bass has declared a local emergency, according to the reporting. The ongoing declaration is intended to help coordinate and sustain the response as crews work to contain the blaze and manage hazards associated with the smoke and difficult operating conditions. No additional details about injuries, cause, or damage scope are included in the provided articles. Overall, the available coverage focuses on the sustained multi-day firefighting effort, the continued complexity of conditions in the warehouse area, and the growing concern about smoke as the incident progresses.