How migrant tragedy unfolded on the high seas off Greece

Protesters hold a banner during a demonstration in front of the parliament building, following a deadly migrant shipwreck off Greece, in Athens, Greece, June 14, 2023. The banner reads: "They made the Mediterranean a sea of the dead. The system of poverty and profits has sunk!" REUTERS/Louiza Vradi

KALAMATA, Greece (Reuters) -As Greece confronts its worst sea disaster in years, questions are mounting about how potentially hundreds of migrants drowned even as their vessel was being shadowed by the Greek coastguard.

At least 78 people died when the fishing vessel flipped and capsized in international waters south-west of Greece early on Wednesday. Authorities rescued 104 people but hundreds are feared missing, with some witnesses saying up to 750 people were aboard.