Authorities heard a single gunshot as they prepared to rip down the final wall to the cabin in which its believed fugitive former LA cop Christopher Dorner had holed himself up in, the Los Angeles Times has reported.
A law enforcement source told the newspaper police had smashed windows, fired tear gas into the cabin and called for Dorner to surrender with a loud speaker.
After getting no response, police used a vehicle to rip down the cabin's walls "one by one, like peeling an onion," according to the official.
The gunshot was then heard and flames quickly engulfed the battered cabin, the official said.
More top news
Anger at the verdict in the shooting of black teenager Michael Brown has left the US deeply divided during its celebration of togetherness.
For most of the country, tomorrow is set to get off to a more pleasant start as it should be drier and brighter with the odd sunny spell.
A man who was abused by John Allen as a child has spoken out as the former care home boss has been found guilty of a further eight charges.