91福利社

In April 2016 a boat carrying 500 people sank in the Mediterranean. Fewer than one in ten of those on board survived. The passengers were migrants, travelling from North Africa to Italy. Survivors spoke of an horrendously overcrowded ship, hopelessly unfit for its human cargo. But other details of the journey remained unclear, including where the passengers set off from, and who organised their deadly journey. John Sweeney reports.