Interstate 5, which has been closed due to the Delta Fire, is seen completely empty in Lamoine, California, in the Shasta Trinity National Forest, on September 6, 2018. (Photos: VCG)

Firefighters light backfire in the Pollard Flat area of California in the Shasta Trinity National Forest on September 6, 2018.

Firefighters monitor flames as backfire spots down a hillside in the Pollard Flat area of California in the Shasta Trinity National Forest, north of Redding, on September 06, 2018.

An outbuilding burns as firefighters struggle to contain backfire in the Pollard Flat area of California in the Shasta Trinity National Forest, north of Redding, on September 06, 2018.

Firefighters struggle to contain backfire in the Pollard Flat area of California in the Shasta Trinity National Forest on September 6, 2018.

A sign is engulfed in flames as firefighters struggle to contain backfire in the Pollard Flat area of California in the Shasta Trinity National Forest on September 6, 2018.