Authorities are investigating the death of a man who died of his injuries a few hours after he rushed past layers of security officers into a massive fire at the Burning Man festival's signature ceremony.

Late Saturday night, Aaron Joel Mitchell, 41, broke through a two-layer security perimeter during the Man Burn event in which a giant, wooden effigy is set ablaze.

Nevada's Pershing County Sheriff Jerry Allen estimated that there was a crowd of about 50,000 people who were present when the festival's crew of firefighters pulled Mitchell out of the blaze.

He was airlifted to the UC Davis hospital burn center in California, where he died Sunday morning. The sheriff said doctors confirmed Mitchell wasn't under the influence of alcohol, but a toxicology report is pending.