Police investigators in Galway, Ireland, have determined that a local man died of spontaneous human combustion, an unverified phenomenon where a person catches fire without an external force.

Michael Faherty, 76, was found in his home lying on his back, completely burned, in December 2010, the Independent reports. Only the floor below him and ceiling above him were damaged.

Faherty’s head was near a fireplace, which was being used at the time of his death, but investigators said it did not contribute to his death. There were no accelerants found at the scene.

Coroner Kieran McLoughlin came to a truly bizarre and seemingly impossible conclusion.

“This fire was thoroughly investigated and I'm left with the conclusion that this fits into the category of spontaneous human combustion, for which there is no adequate explanation,” McLoughlin told the Independent.