A northern California wildfire injured several people on Friday and forced the evacuations of thousands.
According to Cal Fire, the blaze had spread over 3,921 acres on Saturday and was 20% contained.
The cause of the fire, which started on Friday near the property of Roseburg Forest Products, remains under investigation.
Rebecca Taylor, the communications director for the company, said it is unclear if the fire started near or on company property.
An evacuation center was set up at the Yreka Community Center.
The Cal Fire Siskiyou Unit said Saturday that large numbers of resources arrived throughout the evening and that personnel engaged in structure defense and established control line.
The wildfire jammed roadways and destroyed multiple homes, pushed by 35-mile-per-hour winds.
A video shared on Twitter by a nearby resident showed large plumes of smoke above a wooded area near Weed.
More than 27,000 customers in the Golden State were without power, including thousands in Weed which were hit on Friday afternoon due to the wildfire.
A heat wave was already expected to put a strain on California's electric grid and its operator had issued Flex Alerts over the past few days.
Allison Hendrickson, a spokeswoman for Dignity Health North State hospitals, said two people were brought to Mercy Medical Center Mount Shasta.
One person was in stable condition and the other was transferred to UC Davis Medical Center, which has a burn unit.
North of the Mill Fire, a second fire, the Mountain Fire, broke out near the community of Gazelle – as prompting some evacuations.
It had scorched more than 1,400 acres as of early Saturday morning and was 0% contained.
Gov. Gavin Newsom declared a state of emergency for Siskyou County and said a federal grant had been received.
The Associated Press contributed to this report.