Nasenet has not seen her son in eight years. In 2015, she left Yafet behind in Sudan to risk the dangerous journey across desert and sea to Europe. She needs Yafet's father's consent to bring him to live with her in Germany. But his father, Biniam, is lost at sea, presumed dead.

They are not alone. Thousands in Europe have lost loved ones crossing the Mediterranean. Psychiatrist Marzia Marzagalia says survivors suffer nightmares, panic attacks and depression. Denied a body to bury or cremate, they live in "emotional purgatoryIn Catholic tradition, the place where sinners go to have their sins purified before moving on to heaven. It is a time of troubled waiting. ".

Since 2014, over two million have tried to reach Europe by boat. At least 25,000 have drowned, making the Mediterranean the world's deadliest migration route.¹ Migrants mostly come from North Africa and the Middle East, escaping war, persecution, poverty, and famine.

Occasionally the crisis makes headlines - like 3 October 2013, when the remains of 366 drowned migrants were found in a wrecked fishing boat off the Italian island of Lampedusa. "For the first time," says Eritrean activist Tareke Brhane, "the sea gave us back the bodies." One of them may have been Yafet's father.

But headlines fade and people forget. The UN calls it an "overlooked tragedy" which is getting worse. Tunisian researcher Nadhem Yousfi says Europe has dug a "graveyard of humans and hope" on its southern border. And something must be done.

Not everyone agrees. Many politicians argue that migrants know the risks when they choose to travel. Rescuing them encourages more to make the voyage. And money spent raising sunken vessels to find bodies could be better spent strengthening borders in North Africa.

"Italy is not Europe's refugee camp," says Matteo Salvini, Italy's deputy prime minister. Last year's elections in Italy saw victory for far-right nationalist Giorgia Meloni under the slogan "stop landings". And in Greece, 24 volunteers who rescued refugees at sea are now on trial for human trafficking.

Others say Europe has a moral duty to prevent deaths and retrieve bodies swallowed by the sea. "Knowing whether your son is dead or not is a fundamental right," argues forensic anthropologistA scientist who analyses human remains to help identify people and investigate suspicious deaths. Cristina Cattaneo. She has spent the last decade helping migrants identify missing relatives.

Cattaneo wants humanitarian corridors to allow people to travel safely to Europe. "There shouldn't be all these dead people," she says. "It's crazy." Campaigners say the EUEuropean Union. An economic and political union of 27 countries. contributes to the death toll by preventing rescue attempts and helping the Libyan Coast Guard intercept and sink migrant boats.

The role of NGONon-governmental organisations. They are groups that are not run by any government. sea rescue is hotly debated. The Italian politician Luigi Di Maio calls them a "migrant taxi service" that helps people smugglers. But political scientist Laura Schmeer says the risk of death has risen to record levels since Italy began to deter rescue missions.

Meanwhile, Nasenet is still looking for Biniam: "He was the father of my son, and now he's dead, and they don't believe me." And as more risk the voyage, her story may become even more common.

Yes: Mediterranean migrants are being treated unequally. Last year, millions of Ukrainian refugees were allowed safely into the EU. Europe could end this tragedy tomorrow by opening humanitarian corridors.

No: There is no easy solution. Human traffickers exploit people's desire to reach Europe. It will be impossible to prevent more deaths as migrant numbers rise. It is a tragedy, but not Europe's fault.

Or... This shocking statistic is part of a much bigger scandal. Climate change will force millions to migrate. Faced with a global crisis, we may need to rethink national borders entirely.

Purgatory - In Catholic tradition, the place where sinners go to have their sins purified before moving on to heaven. It is a time of troubled waiting.

Forensic anthropologist - A scientist who analyses human remains to help identify people and investigate suspicious deaths.

EU - European Union. An economic and political union of 27 countries.

NGO - Non-governmental organisations. They are groups that are not run by any government.