Hours after the cabin went up in flames, Los Angeles police said no body had yet been recovered from the smouldering ruins, despite several media reports to the contrary, because the site was "still too hot" for police to enter and search.
Left uncertain was the fate of the gunman who authorities said earlier they presumed to be fugitive former Los Angeles policeman Christopher Dorner, 33, suspected of a revenge-fueled killing spree in the region.
The death of a sheriff's deputy in the shootout at the cabin, located in the snow-covered mountains of the San Bernardino National Forest, brought to four the number of killings Dorner is suspected of committing.
An angry, rambling manifesto posted last week on Dorner's Facebook page claimed he had been wrongly terminated from the Los Angeles Police Department in 2008. He vowed to seek revenge by unleashing "unconventional and asymmetrical warfare" on law enforcement officers and their families.
Police tracked the gunman to the forest cabin after he broke into another home near the ski resort community of Big Bear Lake, tying up a couple there and stealing their pickup truck, authorities said.
A state game warden apparently on the lookout for Dorner exchanged gunshots with the driver of the stolen truck. The vehicle was later abandoned and the driver fled into the forest.
Officials of the San Bernardino County Sheriff's Department said the gunman then barricaded himself inside another cabin and engaged in a shootout with police as they closed in on him.
In addition to the sheriff's deputy who was shot and killed, another was wounded, Sheriff John McMahon told reporters.
After a lull in the gunfire, the cabin suddenly caught fire, and television news footage showed smoke and flames engulfing the structure in a heavily wooded area.
San Bernardino County sheriff's spokeswoman Cindy Bachman said a "smoke bomb" had been set off at the cabin before the fire started, but she was uncertain if it had been detonated by the gunman or by law enforcement authorities.
"There is a subject barricaded in the cabin and at this time that cabin is on fire," Bachman told an earlier news briefing.
"If there is someone inside the house, he is armed and already killed one of our sheriff's deputies, so we're not going to allow anyone to go near that house."
Los Angeles Police Chief Charlie Beck has called the search for Dorner the most extensive manhunt in the region's history.
Dorner's last confirmed encounter with authorities came early last Thursday, when police said he ambushed two policemen at a traffic light in Riverside, about 100km east of Los Angeles. One of those officers was killed and the other wounded.
Dorner, a former Navy officer, is also suspected of having exchanged gunfire on Thursday with police and wounding one officer in nearby Corona.
Last Wednesday, he was named as a suspect in the slayings of a campus security officer and his fiancee, the daughter of a retired Los Angeles police captain. In the manifesto posted on his Facebook page, Dorner blamed the captain for his dismissal from the LAPD.
The couple, Keith Lawrence, 27, and Monica Quan, 28, an assistant college basketball coach, were found shot dead on February 3 in their car on the top level of a parking structure in the city of Irvine, south of Los Angeles.
Quan's father, Randy Quan, had represented Dorner in disciplinary proceedings that led to his dismissal after a police inquiry found Dorner had made false statements accusing a superior officer of using excessive force, police said.
Riverside County Prosecutors have formally charged Dorner with one count of first-degree murder and three counts of attempted murder in connection with Thursday's shootings of police officers.
Authorities posted a $1 million reward for information leading to Dorner's capture, an amount they said was the largest ever offered in a Southern California criminal investigation.