CINCINNATI, OH (FOX19) - We may never know what happened to Otto Warmbier during his 17-month detainment in North Korea, the Hamilton County coroner said Wednesday.
Warmbier was evacuated in a coma on June 13 and returned home to his family in Cincinnati. He died several days later.
Dr. Lakshmi Sammarco listed the 22-year-old's cause of death as brain damage from oxygen deprivation through "an unknown insult more than a year prior to death."
But Sammarco said it would be impossible to determine how Warmbier received the traumatic brain injury. When asked if he was tortured, she said she can't be sure what caused the lack of oxygen to the brain.
"We don't know what happened to him to cause that brain damage," said Sammarco at a press conference Wednesday. "That's the bottom line."
In an interview with Fox and Friends Tuesday, his parents said North Korea "destroyed" their son and that he was "jerking violently, making inhuman sounds" when he arrived home in a coma.
"There are involuntary movements and sounds and grunts that happen. And when you're not familiar with patients that have that kind of brain damage, it's going to be alarming," Sammarco said in response to a question about the family's statement.
Warmbier suffered the brain damage more than one year before he returned to Ohio. His healthy skin and body weight suggest he had "round the clock care" in North Korea - even while in a coma, Sammarco said.
She opened the news conference by saying she had received questions about Warmbier's teeth, and said there was no evidence of trauma to his teeth.
His father told Fox and Friends that it appeared someone had taken a pair of pliers and re-arranged his bottom teeth.
His body showed no evidence of healed bone fractures or serious scars. However, the coroner's office found a scar that "we really couldn't explain through medical instrumentation," Sammarco said.
Warmbier's manner of death remains undetermined. His family did not want the coroner to perform an autopsy on his body. Sammarco said an autopsy would have provided very few answers about the cause and manner of his death.
Warmbier was accused in January 2016 of trying to steal a propaganda banner while visiting the country.