The captain and a crew member are among the boat's 28 survivors; the U.N. says more than 800 would-be migrants died after cramming themselves onto the 66-foot boat.
With record numbers fleeing the Middle East and Africa in overcrowded boats, the Catrambone family is conducting private rescue operations in the Mediterranean Sea.
The refugees and migrants had tried to cross the frigid Mediterranean in open vessels without food and water. The estimate comes from the U.N. refugee agency, which spoke to survivors.
A new report says thousands of people are being deported without their belongings, money or ID. And that's creating even more hardship for Mexican migrants when they return home.
Migrants from Africa and Afghanistan have poured into Calais, hoping to seek asylum in Britain across the channel. But few succeed, leaving an estimated 2,000 in limbo in the French port city.
The International Organization for Migration says the incident took place last week when people smugglers rammed a vessel carrying hundreds of refugees hoping to reach European waters.
Spain is dealing with its biggest migration crush in decades. More than 1,200 people this week alone have landed on the country's Mediterranean coast in flimsy rafts and boats.
They are being held by a militia paid to deal with the flow of illegal immigrants into and through Libya. Most will be deported. Libya has long been a magnet for migrants from the region. European countries are now criticizing its policies, but Libyan authorities say they need help to secure the country's borders.