Jung Sung-wook's teenage son was one of more than 300 people who died when an overloaded ferry capsized off South Korea's southern coast in April 2014. Ten years on, he is still reckoning with the horror of the country's worst ever maritime disaster. One of the last text messages Jung's son sent was to his mother, telling her that the ferry had tilted to 45 degrees -- prompting his father to race to scene of the rescue operation in a desperate bid to find his child. "It was so chaotic, in a word, it was hell," he says, recalling a scene at the school gymnasium in southern Jindo where survivors were being taken. IMAGES AND SOUNDBITES