Yoo was chairman of Chonghaejin Marine, which operated the MV "Sewol" ferry between Incheon and Jeju when it sank. The sinking became known as the Sewol ferry disaster. When the Incheon District Court issued a warrant on 22 May 2014 for his arrest, Yoo went into hiding and was South Korea's most-wanted fugitive. In June 2014, police discovered a body that was confirmed to be Yoo's in July 2014. An investigation into the cause of death was inconclusive because the body was too decomposed.