Sprinklers Failed in Million-Square-Foot Medical Supply Warehouse in Tracy, CA

Tracy Fire Chief Randall Bradley said firefighters encountered water issues and explosions during the operation that will continue for days.

Aldo Toledo, Lucy Hodgman, Megan Fan Munce

San Francisco Chronicle

(TNS)

A massive warehouse fire that erupted in Tracy on Thursday afternoon could take up to four days to extinguish, officials said.

The fire destroyed the 1 million-square-foot facility and sent embers downwind that started several smaller fires in the area and threatened a nearby FedEx facility.

Billowing black smoke was visible from the Bay Area on Thursday evening, and residents closer to the fire were warned to stay indoors to avoid breathing in smoke, ash or potentially toxic substances.

“This is such a unique fire,” Tracy Fire Department Chief Randall Bradley said Thursday evening. “A million-square-foot fire is an extremely rare fire in the United States.”

Bradley said “the whole building was engulfed” within 20 minutes, in part because of hot and dry conditions in the area and a lack of pressurized water at the facility during the initial firefight.

Firefighters responded around 1 p.m. to Medline, the largest privately held manufacturer and distributor of medical supplies in the U.S. located near the 5700 block of Promontory Parkway, west of the city’s downtown, officials said. Firefighters found a growing blaze on the warehouse’s roof, which rapidly spread as water supply problems caused the building’s fire water system to fail. Explosions could be heard as the blaze spread.

Neither of the two warehouse facility’s sprinkler systems appears to have gone off, according to Bradley.

“We don’t know why those fire hydrants weren’t pressurized,” he said, noting that the fire pumps and alarm systems were last tested in January.

Despite the scale of the fire, officials reported no injuries to firefighters or employees. Medline and other nearby businesses were evacuated, authorities said.

“Although we had a very significant fire, the fact that no firefighters were injured and all employees evacuated quickly is astounding,” Bradley said.

The cause of the fire was still under investigation Thursday evening, as more than 120 firefighters from across the region continue to fight the blaze.

Medline last year reported storing large amounts of liquid bleach, isopropyl alcohol, lye and sulfuric acid, according to records from the California Environmental Protection Agency.

The company also reported storing 60 to 119 gallons of xylene a day, according to CalEPA records. Xylene, a widely used solvent in tissue processing and staining, is toxic to humans. When inhaled, it can cause headaches, dizziness, nausea and vomiting, which gets worse with longer exposure, according to an article published in the Journal of Oral and Maxillofacial Pathology.

Jaime Holt, chief communications officer for the San Joaquin Valley Air Quality District, said the agency has not been able to confirm whether the warehouse was storing any toxic substances that could be hazardous to air quality. Fire officials said they didn’t believe there was anything of concern, according to Holt.

But the local air district put out a warning cautioning residents in San Joaquin and Stanislaus counties to stay indoors, shut windows and doors and use air filters. Smoke from the fire could be seen pouring over the East Bay hills Thursday afternoon, but it was not expected to cause any air quality issues in the region, the Bay Area Air District said.

Medline told the Chronicle it was aware of the fire.

“All Medline employees and on-site personnel are accounted for,” a spokesperson for the company said. “We are coordinating closely with local authorities and first responders as we assess the fire’s impact and will share more details as they become available.”

High winds carried embers from the Medline fire south toward the nearby FedEx facility, igniting large pallet storage areas and several big-rig trailers, the city said. The exterior of the building caught fire, but crews were able to bring the flames under control, according to the South San Joaquin County Fire Authority.

A FedEx spokesperson said all employees were “safe and accounted for” Thursday evening, and that the fire had not engulfed the main facility as of 6:30 p.m.

“Crews aggressively attacked these fires and continue working to protect the FedEx facility and surrounding properties,” the city said. “Additional spot fires occurred in the vicinity of Schulte Road and Larch Road, as well as near Tracy Municipal Airport.”

The spot fires were contained by 5 p.m. Thursday. Although water supply issues at the Medline facility impacted initial firefighting efforts, municipal water pressure was still stable Thursday afternoon, the city said.

Larissa Gomez, a shift supervisor at a nearby Starbucks, said throngs of workers could be seen walking toward a rest stop center near Interstate 580. Gomez said police blocked off roads in the area and that many of the warehouse workers were gathered at nearby businesses, including a gas station, Taco Bell and Starbucks, where employees distributed water to those seeking relief from the heat.

“There are probably a dozen people — honestly, more than that — sitting in the shade, " she said. “I saw a lot of factory workers and FedEx workers walking this way because they weren’t able to reach their cars.”

Meanwhile, San Joaquin Valley Air Quality District advised concerned residents to search for their ZIP code on AirNow.gov to monitor air quality near them. As of 7 p.m. Wednesday, sensors close to the fire reported moderate air quality.

Movement in the atmosphere was keeping most of the smoke aloft, according to Holt. But the district predicted that would change overnight as the sun set, temperatures dropped and winds died down, allowing smoke to move more slowly and build up in concentration. Smoke could travel as far as Modesto, Merced, Fresno, and King and Kern counties, officials said.

Police earlier Thursday warned people to avoid the area and find alternative routes if possible. Promontory Parkway was closed while crews work to contain the fire, police said. Tracy police officers are on the scene assisting with evacuations and directing traffic.

Drivers in the area should expect delays, police said.

© 2026 the San Francisco Chronicle. Visit www.sfchronicle.com. Distributed by Tribune Content Agency, LLC.

 

Crews are responding to a large fire at a Medline Industries distribution center in Tracy on Thursday afternoon, the San Joaquin County Office of Emergency Services said. KCRA 3 is your home for California breaking news and weather. For your latest California news and weather visit: https://www.kcra.com/ For licensing inquiries: https://www.kcra.com/licensing
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