A Los Angeles man burned to death at a West Hollywood carnival Halloween night while the party carried on around him.

Some of his fellow partiers poured water on Gilbert Estrada or tried to smother the fire using their jackets, witnesses told the Los Angeles Times, but others took pictures, recorded video or kept dancing.

The 51-year-old died in hospital after his burlap sack and straw sniper costume lit fire, engulfing his body in flames. Investigators told the newspaper Estrada might have lit the fire himself while trying to ignite a cigarette. A witness said he saw the fire start at Estrada's hood and then travel to his back and the rest of his clothes.

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“People were chanting, clapping, filming and taking pictures like it was some kind of cool, funny thing and not realizing it was a guy who was suffering in a really bad condition," one bystander, Derek Easley, told the Los Angeles Times.

Footage uploaded to YouTube shows Estrada surrounded by a ball of fire in the centre of a crowd of people. Some rush to help him while others laugh and yell that he's crazy. A warning, the video contains strong language.

CBS Los Angeles reported Estrada attended the party with his girlfriend. Detectives are waiting for the results of an autopsy.