(ABC NEWS) -- When Otto Warmbier, the American college student who was imprisoned in North Korea for 17 months, returned home to Ohio last June on an airplane, he was blind, deaf and "jerking violently, making these inhuman sounds," his parents said today in an interview.
"We thought he was in a coma, but you couldn't call it a coma," his mother, Cindy Warmbier, said on Fox News' "Fox & Friends." "What we pictured ... was that Otto would be asleep and maybe in a medically-induced coma. And then when our doctors here would work with him, and he'd get the best care and love, that he would come out of it."
His father, Fred Warmbier, recalled that as he and his wife walked toward the inside of the plane, "We heard this howling, involuntary, inhuman sound."
Their son "was jerking violently, making these inhuman sounds," he said.
"Otto had a shaved head. He had a feeding tube coming out of his nose," Fred Warmbier described. "He was staring blankly into space, jerking violently. He was blind. He was deaf. As we looked at him and tried to comfort him, it looked like someone had taken a pair of pliers and rearranged his bottom teeth. Within two days of Otto being home, his fever spiked to 104 degrees. He had a large scar on his right foot."
The Warmbiers were told that their son had contracted botulism after his trial in North Korea and was given a sleeping pill. But he never woke up.
Otto Warmbier died on June 19, 2017, at the age of 22, just six days after he was evacuated from North Korea.
He had been arrested in North Korea for allegedly trying to steal a propaganda poster from a restricted area in January 2016 while visiting the country on a sightseeing tour. After a one-hour trial in March 2016, he was convicted and sentenced to 15 years of hard labor.
"They kidnapped Otto, they tortured him," Fred Warmbier said.
"They destroyed him," Cindy Warmbier added.
She said she thinks her son was sent home because he was going to die.
"No mother, no parent should ever have gone through what we went through," she said. "And the fact that Otto was alone all that time with no one to comfort him is inexcusable. And whatever -- whatever happened, I mean, why would do you this?"
"How can you get what a terrorist country does?" Fred Warmbier added. "They are terrorists. This is what they do."
He went on, "We owe it to the world to list North Korea as a state sponsor of terror. Now we see North Korea claiming to be a victim and that the world is picking on them, and we're here to tell you, North Korea is not a victim. They're terrorists."