Thousands of people have been forced to flee after a wildfire tore through an area of northern California, killing a bulldozer operator as he fought to contain the blaze.
Three firefighters have also been injured and dozens of homes destroyed by the blaze.
Flames swept through the communities of Shasta and Keswick before jumping the Sacramento River and reaching Redding, a city of about 92,000 people - the largest in the region.
A fire official said the blaze was “taking down everything in its path”. He added: “It’s just a wall of flames. It’s nonstop.”
Crews found the body of the bulldozer operator who was hired privately to clear vegetation in the blaze’s path.
The fire burned over the operator and his equipment, making the man the second bulldozer operator to be killed in a California blaze in less than two weeks.
“It’s just chaotic. It’s wild,” the spokesman said. “There’s a lot of fire, a lot of structures burning.”
He said many people in Redding did not seem prepared for the blaze to reach their city.
“When it hit, people were really scrambling,” he said. “There was not much of a warning.”
Traffic out of the city was backed up, with journeys that normally take 20 minutes reaching two-and-a-half hours as residents fled to safety.
Firefighters tried in vain to contain the blaze on Thursday but flames kept jumping their lines.
The 45-square-mile fire that began on Monday tripled in size overnight amid scorching temperatures, low humidity and windy conditions.
Wildfires throughout the state have burned through tinder-dry brush and forest, forced thousands to evacuate homes and forced campers to pack up their tents at the height of summer.
Governor Jerry Brown declared states of emergency for the three largest fires, which will authorise the state to rally resources to local governments.
The wildfires have dispatched firefighters to all corners of the state amid an oppressive heatwave.
A huge forest fire continued to grow outside Yosemite National Park. That blaze killed 36-year-old Braden Varney, a heavy equipment operator for the California Department of Forestry and Fire Protection whose bulldozer rolled over into a ravine on July 14.
About 100 homes were still under threat in the San Francisco Bay community of Clayton, although firefighters had stopped the progress of a small fire there after one house burned.
Hundreds of miles to the south, winds picked up and sent flames rushing downhill on the flanks ofsSouthern California’s Mount San Jacinto.
Helicopters making water drops and air tankers pouring red flame retardant circled overhead as flames burned both sides of the main road leading to the scenic town of Idyllwild.
The blaze erupted on Wednesday and quickly turned into a wall of flame that torched timber and dry brush. In a matter of hours, the so-called Cranston Fire grew to 7.5 square miles.
About 3,000 residents were under evacuation orders on Thursday in Idyllwild and several neighbouring communities.