Where are California wildfires burning? See maps and air quality

Multiple wildfires are burning across Southern California, with investigators examining unusual ignition sources. The Santa Rosa Island Fire has burned over 17,500 acres and is 44% contained, possibly sparked by an SOS flare from a stranded boater.

The Sandy Fire may have been started by a tractor striking a rock. Air quality alerts are in effect for millions in the Inland Empire and Los Angeles area due to wildfire smoke.

Officials warn of health risks from fine particulate matter, especially for vulnerable populations.