A man attending an illegal cockfight in California died after being stabbed in the leg by one of the birds, officials have said.
The cock had a knife attached to its limb to take part in the gambling fight in Tulare County, central California.
Jose Luis Ochoa, 35, was declared dead in hospital where he arrived some two hours after being injured.
The coroner's report said he had suffered an accidental "sharp force injury" to his right calf.
It was not immediately clear if a delay in seeking medical attention was a factor in the death.
"I have never seen this type of incident," Sgt Martin King, who had worked in the sheriff's department for more than two decades, told the Bakersfield Californian on Sunday, when the incident happened.
Other dead roosters and materials suggesting cockfighting were found at the location, reports said, but no arrests were made.
Mr Ochoa, reportedly a regular participant in organised cockfights, had already been fined for owning or training an animal for fighting, according to court records cited by the newspaper.
Though cockfighting is illegal in the US, California is a popular destination state for people involved in the sport as raising the gamecocks, organising matches and attending fights as a spectator are all classified as misdemeanours on the first offence, rather than more serious criminal offences in the state.