On the evening of September 27, 1994, M/S Estonia set sail from the quay in Tallinn. There were 989 people on board. Only 137 would survive the night. 852 people lost their lives in the biggest disaster in Swedish history and the biggest shipwreck in peacetime Europe. The ship sank in half an hour and most never got out. But what actually happened? And how could that happen?—TV4