Sheriff's spokesman Steve Whitmore says the four men and a woman refused to leave the Angeles National Forest two days ago. On Monday they called for help because they were unable to leave a ranch in Gold Canyon.
Whitmore says a sheriff's helicopter had planned to help but the flames are too intense and authorities must wait for the fire to pass by before going in.
Authorities say three other people were badly burned over the weekend after refusing evacuation orders. Two of them sought refuge in a hot tub.
The fire that burned at least 53 homes was moving north, south and east through the rugged foothills northeast of Los Angeles. Despite the lack of wind, it surged without letup by running through steep granite canyons and feeding on brush that had not burned for 40 years to a century, fire officials said.
"It's burning everywhere," U.S. Forest Service spokeswoman Dianne Cahir said. "When it gets into canyons that haven't burned in numerous years, it takes off. If you have any insight into the good Lord upstairs, put in a request."
The fire had burned 134 square miles of brush and trees by early Monday and was just 5 percent contained.
About 12,000 homes, as well as communications and astronomy centers atop Mount Wilson, were threatened by fire.
At least 6,600 homes were under mandatory evacuation orders and more than 2,500 firefighters were battling the flames. On the blaze's northwestern front, two firefighters were killed Sunday when they drove off the side of a road on Mount Gleason near the city of Acton.
The victims were fire Capt. Tedmund Hall, 47, of San Bernardino County, and firefighter Specialist Arnaldo "Arnie" Quinones, 35, of Palmdale. Hall was a 26-year veteran, and Quinones had been a county firefighter for eight years.
"Our hearts are heavy as we are tragically reminded of the sacrifices our firefighters and their families make daily to keep us safe," Gov. Arnold Schwarzenegger said in a statement.
With flames about a half-mile away from the communications and astronomy centers on Mount Wilson, crews planned to set more backfires and planes dropped fire retardant around the mountaintop complex, which hold transmitters for more than 20 television stations, many radio stations and cell phone providers.
Television stations said if the antennas burn, broadcast signals would be affected but satellite and cable transmissions would not be.
Two giant telescopes and several multimillion-dollar university programs are housed in the century-old Mount Wilson Observatory. The complex of buildings is both a historic landmark and a thriving modern center for astronomy.
The sheer length of the fire meant that it threatened homes ranging from scattered ranches to multimillion-dollar estates in luxury enclaves.
Mandatory evacuations were in effect for neighborhoods in Glendale, Pasadena and other smoke-choked cities and towns north of Los Angeles.
"Our neighbors sent us photos of all the other houses that are lost," said Beth Halaas, who lost her house in Big Tujunga Canyon, one of the many communities under mandatory evacuation.
The fire was the largest of many burning up and down California after days of triple-digit temperatures and low humidity. The National Weather Service said a red flag warning for extreme fire conditions remained in effect for the mountains of Central and Southern California.
"We know what's coming this afternoon, just the sheer heat and the low humidity," Bill Peters, a spokesman with the California Department of Forestry and Fire Protection, told KTLA-TV.
"The fire makes its own path," Peters said. "It just flows with the terrain. It'll run very quickly uphill and because of the dynamics and the decadent vegetation being so dry, it will drive itself downhill, where normally you need a wind to do that."
Northeast of Sacramento, a fire destroyed 60 structures, many of them homes in the town of Auburn. The fire had wiped out an entire cul-de-sac, leaving only smoldering ruins, a handful of chimneys and burnt cars.
Rick Lund, whose house is nearby but escaped the fire, stood at the end of the cul-de-sac of about 10 homes, watching firefighters attend to what once were the homes of friends and neighbors.
"It's right there," he said, pointing to a house of his 11-year-old daughter's close friend. "Or it was."
The fire had blackened 275 acres amid high winds and was 50 percent contained Sunday night, CalFire spokesman Daniel Berlant. The governor declared a state of emergency in the Sierra foothills area because of the fire, which began Sunday afternoon.
About 30 people waited anxiously at an evacuation center in the Rock Creek Elementary School, including Pam and Stephen Incerty.
"If there's nothing there when we get back, we won't rebuild," Stephen Incerty said of their home on five tree-covered acres of rolling hills. "There'd be no trees, just dirt."
In Mariposa County, a nearly 7-square-mile fire burned in Yosemite National Park and forced the evacuation of about 50 homes. The blaze was 50 percent contained Sunday, said park spokeswoman Vickie Mates. Two people suffered minor injuries, she said.
Hot, dry and windy conditions also helped fan a monthlong wildfire in rural Utah, where residents in the town of New Harmony were told to leave their homes as the blaze flared up over the weekend. The lightning-sparked fire has already destroyed three houses and blackened more than 12 square miles in the Pine Valley Wilderness area.
Williams reported from Auburn, Calif. Associated Press writers Christopher Weber and Andrew Dalton in Los Angeles contributed to this report.