His cause of death has been ruled undetermined. There were no physical injuries like broken bones or gunshot wounds found in the autopsy, according to Reuters.
Maddux's mother reported him missing in May 2008.
A demolition crew that was tearing down the abandoned cabin found his remains, which needed to be identified through dental records and the missing tip of his right index finger. He damaged his hand in a bicycle accident as a child, The Gazette reported.
The coroner believes Maddux possibly got stuck shimmying down the chimney. But officials don't know why he was trying to get into the cabin that was sitting abandoned.
Chuck Murphy said that the cabin was purchased 60 years ago by his parents. He'd check on the property, and said, "It smelled bad."
It was a rental before it was left vacant at least a decade ago.
Maddux's sister Kate believed that her brother left home, starting a new life, The Gazette reported.
"I have always chosen to believe that this was the case," Kate said. "I have expected Josh to return home to my father's house at any time."