Coroner contradicts Otto Warmbier's parents on his time in North Korea

Otto Warmbier left Cincinnati as a healthy 22-year-old and returned in a coma from which he would never awaken. Nothing in the intervening time is certain — was he tortured while held prisoner in North Korea? How did he fall into the coma? His parents, coroner Lakshmi Sammarco and the North Korean government all disagree.