An Amagansett attorney who played a pivotal role in the return of Otto Warmbier from North Korea says his death is unimaginable and unacceptable. 

The University of Virginia student had been detained for nearly 18 months after being convicted of hostile acts against the state. He admitted that he stole a political sign from his hotel.

Michael Griffith, a University of Virginia alumnus with experience with international criminal law, says he had been working with former UN ambassador Bill Richardson to try and bring the 22-year-old home.

Griffith says he traveled from his Amagansett home to North Korea last August in the hopes of making contact and securing the young man's release. It didn't work. Neither did nearly two dozen attempts by Richardson.  

Warmbier was returned to the United States last week in a coma. He had been in that condition for a year. 

"We have to send a message to let these people know that this is not the way that human beings treat each other or countries should treat each other," he tells News 12. 

He also says that consequences against North Korea should be "swift and severe."