Otto Warmbier, the American college student who was detained in North Korea for more than a year before being released last week, has died, his family said Monday.

Warmbier, 22, was released from North Korea June 12 in a comatose medical state of “unresponsive wakefulness,” according to physicians. He had been receiving intensive care in Cincinnati since then.

Monday, Warmbier’s family announced that he had died.

“It is our sad duty to report that our son, Otto Warmbier, has completed his journey home. Surrounded by his loving family, Otto died today at 2:20pm,” the statement said. “The awful torturous mistreatment our son received at the hands of the North Koreans ensured that no other outcome was possible beyond the sad one we experienced today.”

The University of Cincinnati Medical Center confirmed the death to WCPO-TV.

At the end of his visit to North Korea, Warmbier was detained in January 2016 allegedly for trying to steal a propaganda sign that praised leader Kim Jong-Un from the Pyongyang hotel he stayed at — an act of “subversion” considered to be a serious crime in the country. He was convicted and sentenced to 15 years of hard labor.

About 17 months after he was arrested, Warmbier was finally released last week and flown back to the United States in a comatose condition. It remains unclear why the University of Virginia student fell into a coma, but physicians say it appears he received brain damage while captive.

Warmbier’s parents have severely criticized the North Korean government and question the accuracy of some of its claims about why their son was prevented from returning to the United States, and how it treated him while in captivity.

Pyongyang has said Warmbier contracted botulism while in detention — a rare toxic bacterial disease that impedes with a person’s ability to speak and see and results in extreme lethargy. U.S. doctors, though, have said they’ve found no trace of the illness.

Warmbier decided to take the trip to North Korea, although the U.S. State Department has warned U.S. citizens to stay away from the dictator-led country. Several other U.S. citizens took the trip with Warmbier, but they were allowed to leave at the end of the five-day visit.