A monster wildfire in northern California has continued to burn unchecked after killing two firefighters, destroying hundreds of structures and sent thousands of frantic residents racing from their homes.
Some 3400 firefighters on the ground and in helicopters and planes battled the 19,500 hectares Carr Fire early on Saturday as it ripped through Redding, a city of 90,000 people, in California's scenic Shasta-Trinity area.
More than 38,000 residents in Redding and elsewhere in Shasta County fled their homes as the fire began to gain speed and intensity on Thursday, destroying 500 structures and leaving Keswick, a town of 450, in smouldering ruins.
The fire, which was just three per cent contained after igniting six days ago, has been fed by high temperatures and low humidity, which were expected for at least the next week, said California Department of Forestry and Fire Protection (CalFire) Director Ken Pimlott.
"This fire is a long way from done," he said.
A bulldozer operator and a member of the Redding Fire Department were killed in the blaze. A Redding hospital said it had treated eight people, including three firefighters.
Local Rob Wright, 61, and his wife stayed to fight off flames with a high-powered water hose.
"We were fortunate enough that the wind changed hours ago, and it is pushing the fire back," said Wright.
"We are just waiting it out ... crossing our fingers and hoping for the best."
The flames erupted into a firestorm on Thursday when it jumped across the Sacramento River and swept into the western side of Redding, about 240 km north of Sacramento, before gale-force winds during the night created a fire "tornado."
"This fire was whipped up into a whirlwind of activity, uprooting trees, moving vehicles, moving parts of roadways," Pimlott said.
Firefighters and police were hustling door to door to usher civilians out of harm's way, said Scott McLean, a CalFire spokesman.
Governor Jerry Brown requested emergency federal assistance to prevent an "imminent catastrophe" as Shasta County tried to find supplies and water for evacuated residents and care for horses and cattle rescued from ranches and farms.
