Death toll rises to 5 in northern California wildfire.
Trump issues emergency declaration as blazes rage across state
Two firefighters died on Thursday, 17 people are missing and tens of thousands have fled their homes.
The fires in Shasta county are being sucked up by strong winds to form "fire tornados" that are uprooting trees and overturning cars, fire officials say.
Firefighters are battling the blaze, which is only 5% contained so far.
The blazes, known as the Carr fire, have destroyed at least 500 structures and are threatening thousands of homes.
The wildfire began on Monday after a car malfunctioned. It has scorched over 48,000 acres (194 sq km) of land - an area larger than the city of San Francisco.
Sherry Bledsoe has confirmed that her grandmother Melody Bledsoe, 70, and her two children Emily Roberts, five, and James Roberts, four, died in the fire, reports say.
They were caught in the path of the fire as they were about to evacuate their home in the town of Redding, NBC reported.
Melody Bledsoe's husband, Ed, earlier described how she had called him while he was out shopping and told him to return home because the fire was getting close to the house.
When he reached home he found it destroyed and surrounded by police tape, he said.
Another relative told NBC that Melody Bledsoe had called police to say they were trapped inside the house but the line went dead during the call.
Two firefighters - fire inspector Jeremy Stoke, and a bulldozer operator who has not yet been named, died trying contain the blaze.