The Carr Fire jumped the Sacramento River over the weekend and moved into the town of Redding, leveling homes, prompting mass evacuations and spawning devastating "firenados" -- or flaming vortexes that shift directions erratically and are powerful enough to toss vehicles, fire officials said.
As of Sunday morning, the blaze had burned 89,194 acres or 139 square miles, which is the size of Detroit, according to the California Department of Forestry and Fire Protection, also known as Cal Fire. The blaze has destroyed at least 536 structures, damaged another 117 and was threatening nearly 5,000 others, officials said.
The inferno is just 5 percent contained.
The bodies of Melody Bledsoe, 70, and her great-grandchildren, James Robert, 5, and Emily Roberts, 4, were recovered from Bledsoe's home in Redding, relatives said.
"Grandma did everything she could to save them," Bledsoe's granddaughter, Amanda Woodley, wrote in a Facebook post after Shasta County Sheriff's officials confirmed the deaths to relatives. "She was hovered over them both with a wet blanket."
James Robert died after he called 911, pleading for help as the flames bore down on his great-grandmother's home, relatives told the San Francisco Chronicle.
The family said authorities told them the boy had called 911 from the house, relatives told the San Francisco Chronicle.
"My nephew called, scared, for help, but they said they couldn't make it in time," said Carla Bledsoe, the children’s aunt, told the newspaper after speaking with sheriff's officials.
Melody Bledsoe's husband, Ed Bledsoe, said he had gone to get supplies when his house caught fire. He said his nephew called him and asked him to come back quickly, but he got stuck in traffic.
"That woman was the best woman I ever seen and them two kids was absolutely angels," Ed Bledsoe told the Sacramento Bee of his wife and great-grandchildren. "They done everything for grandma and grandpa, everything."
The number of people killed in the Carr Fire climbed to six. On Sunday, authorities said another person had been confirmed dead.
"A grand total of six people have been killed," said Sheriff Tom Bosenko of Shasta County.
The latest person has not been identified, Bosenko said. The individual, who was found in an undisclosed residence, was told to leave because of the fire but declined to do so, he added.
"In the most recent one we confirmed that the person did receive evacuation notices and did not evacuate," Bosenko said.
The fire, which started on Monday, also killed Don Ray Smith, an 81-year-old bulldozer operator who was working with fire crews to try to bring the fire under control, officials said. Redding Fire Department Inspector Jeremy Stoke was also killed battling the blaze, officials said.
Nearly 40,000 people have been displaced by the blaze, which was spreading on three fronts, Cal Fire officials said on Sunday.
"It's a very large event with very high speed and very high temperatures that are going to last a couple of days," Sacramento Firefighter Chris Harvey said during a community meeting in Redding Saturday. "The fire still has very explosive behavior."
The origins of the fire have been traced to the "mechanical failure" of a vehicle in Whiskeytown, which is about 10 miles northwest of Redding, officials said.
Fanned by gusts of up to 60 miles per hour and fueled by dried-out vegetation, the fire more than doubled in size between Friday and Saturday, according to Cal Fire.
Nearly 3,400 firefighters are battling the blaze from the ground and in the air, as officials have deployed 17 helicopters, 334 fire engines, 68 bulldozers, and 65 water tenders.
Bret Gouvea, Cal Fire incident commander for the Carr fire, said firefighters are facing other challenges.
"We have noticed that there are drone footages online. Folks flying drones over this. That poses a huge safety risk to our folks," he said.
"If you fly, we cannot," he added, saying authorities have to ground their aircraft because of the drones.
Four evacuation centers have been opened in the area.
"Extreme fire conditions continue to challenge firefighters last night," Cal Fire said in a statement released on Sunday. "Erratic winds and hot dry conditions resulted in greater growth and increased fire behavior during night operations."
Firefighters are getting no relief from the weather. Temperatures in the Redding area are forecast to reach 103 degrees on Sunday, Robert Baruffaldi, a meteorologist for the National Weather Service told ABC News.
"There's so much smoke up there, it's actually keeping the temperature down by about 10 degrees," Barufaldi said.
He said the last significant rain in the Redding area was back on May 25. He added that while a cooling trend is expected toward the end of this week, no rain is in the forecast.
Still, Gouvea said fire officials are feeling "optimistic."
"Rather than being in the defensive mode on the fire all the time, we're starting to make some good process out there," he said.