Fire officials said the sprinkler system wasn’t working inside a medical supply warehouse in Tracy that was gutted by fire on Thursday.

There have been no injuries reported in the blaze, which broke out shortly before 1 p.m. at the 1 million-square-foot Medline Distribution Center, according to the South San Joaquin County Fire Authority. 

Crews were hampered in fighting the fire because the warehouse’s sprinkler system didn’t appear to be working and the water pressure was too low at fire hydrants inside the complex, Fire Chief Randall Bradley said. 

The medical supply warehouse is located in the 5700 block of Promontory Parkway, just south of Interstate Highway 205 and west of the downtown area.

Several agencies were at the scene Thursday evening, with an estimated 200 fire crews and about 100 support personnel to cover other incidents, including two commercial warehouse fires and smaller grass fires.

While the Medline Warehouse was consumed by fire, an additional blaze broke out at a nearby FedEx warehouse, with pallets and multiple big rig trailers catching fire, the fire department said.

“Crews performed an aggressive fire attack to bring that fire under control,” the department said on social media Thursday evening. “The exterior of that building did catch fire, however, personnel were able to keep the fire from engulfing the building.”

The cause of the fire is under investigation. Fire officials said Tracy’s fire stations remain fully staffed, with neighboring agencies covering the city.

Residents are asked to avoid the area and those living in the area should shelter in place due to heavy smoke.

Tracy’s city manager declared a local state of emergency to ensure all available resources and emergency response capabilities are available.

In addition, the San Joaquin Valley Air District issued an air alert due to smoke from the fire, which is billowing over parts of San Joaquin and Stanislaus counties. 

Winds in the area are expected to send smoke inland and southward along the western and central portions of the San Joaquin Valley Thursday evening and overnight, according to the air agency.