A large fire destroyed a medical supply warehouse in Tracy, California, on Thursday afternoon, forcing evacuations and sending thick smoke into the sky. The blaze broke out at a Medline Industries facility around 1 p.m. and quickly spread through the building, officials said.
The fire led to evacuations at the warehouse and nearby industrial sites, including a FedEx facility and an Amazon warehouse. Workers in the area were moved to safety as smoke and debris spread into surrounding neighborhoods.
Authorities confirmed that no injuries have been reported. However, the fire caused major disruption across the industrial zone and raised concerns about air quality due to heavy smoke.
South San Joaquin County Fire Authority Chief Randall Bradley said the fire is believed to have started on the roof of the Medline building. When firefighters arrived, they found intense flames already spreading across the structure.
He said extreme weather conditions made firefighting efforts difficult. High winds, high temperatures, and low humidity all contributed to the rapid spread of the fire and slowed response efforts.
Fire crews were unable to enter the building due to safety risks. At the same time, the sprinkler system did not activate, and water pressure issues at nearby hydrants further complicated the response.
Officials said they are still investigating why the sprinkler system failed. Deputy Chief Brian Bagley said the system had been recently tested, but it did not operate during the fire.
Without sprinkler support, the fire spread quickly and fully engulfed the warehouse in less than an hour. Officials described it as an unusually severe industrial fire that is rarely seen at this scale.
Chief Bradley said crews will likely continue working on the site for several days to fully extinguish remaining hotspots and secure the area.
At the time of the fire, about 120 employees were inside the facility out of a workforce of roughly 900. All employees were safely accounted for, according to company statements.
The fire also triggered smaller secondary blazes in nearby areas. One of these fires spread to a FedEx warehouse but was later fully extinguished by emergency crews.
Despite containment efforts, air quality remains a serious concern for nearby communities. San Joaquin County officials warned that smoke contains toxic gases, carcinogens, and at least one neurotoxin.
Residents in surrounding areas have been advised to stay indoors, keep windows and doors closed, and avoid exposure to outdoor air until conditions improve.
Medline Industries, which describes itself as a major provider of medical and surgical products, confirmed that all affected employees have been accounted for and are safe.
Officials in Tracy allowed some businesses in the area to resume limited operations on Friday, although cleanup and safety checks are still ongoing.
Fire investigators are continuing to examine the cause of the blaze, including the role of rooftop conditions, weather factors, and possible system failures.
Authorities have described the incident as one of the most complex warehouse fires in recent regional history, due to its size, speed, and environmental impact.
The situation remains under review as crews continue monitoring air quality and structural damage in the industrial area.
