Fire at medical supplier Medline in Tracy, city of more than 100,000 residents, is affecting the air quality California firefighters continued to battle a blaze on Saturday that had engulfed a roughly 1m sq ft warehouse, causing officials to warn residents over unhealthy air quality. The fire has been raging at the medical supplier Medline Industries’ warehouse in Tracy, a city of more than 100,000 residents located about 55 miles (90km) east of San Francisco. Officials expect to be battling the fire for a few more days.