Otto Warmbier. Pic/AFP

An American university student held prisoner in North Korea for 17 months died at a Cincinnati hospital on Monday, just days after he was released from captivity in a coma, his family said. Otto Warmbier, 22, who was arrested in North Korea while visiting as a tourist, had been described by doctors caring for him last week as having extensive brain damage that left him in a state of "unresponsive wakefulness."