A fast-growing northern California wildfire killed a second firefighter on Friday after high winds drove it into the city of Redding, prompting mass evacuations, destroying scores of homes and threatening some 5,000 other dwellings and businesses, officials said.

Flames raging in California's scenic Shasta-Trinity area erupted late Thursday into a firestorm that jumped across the Sacramento River and swept into the western side of Redding, home to about 90,000 people, forcing residents to flee for their lives.

Firefighters and police "went into life-safety mode," hustling door to door to usher civilians out of harm's way, said Scott McLean, a spokesman for the California Department of Forestry and Fire Protection (CalFire).

Erratic winds blowing with gale force on Thursday night whipped the blaze into a frenzy, creating fire tornadoes that uprooted trees and tore into structures. "It was like a Tasmanian devil," McLean told Reuters.

Some 37,000 people remained under evacuation orders on Friday, as flames continued to burn in pockets of the city's west side, he said.

CalFire reported 65 structures destroyed by the blaze, but McLean called that tally a "placeholder" figure that would grow significantly, with the number of homes lost likely to run into "the hundreds" as the scope of devastation was fully assessed.

Nearly 5,000 homes were listed by CalFire as threatened.