Generation X: May 2017

This year alone over 40,000 migrants have crossed the Mediterranean, many of them are Nigerians. The BBC's Martin Patience has been to Nigeria's Benin City where many of the migrants start their journey.

It was the most difficult decision Kelvin Imasuen ever made - he would risk everything in a bid to reach Europe.

"I just had the belief I would get there," he told me, sitting outside his mother's dilapidated home on the outskirts of Benin City.

But he was to learn the cost of the dangerous journey in the most devastating way.

Kelvin hoped to go to university, but after his father died the family was plunged into poverty. Kelvin was barely scraping together a living working at a building site.

He was earning at most $2 (£1.55) a day and he says he could not afford the university fees.

Instead, like tens of thousands of other Nigerians hoping to reach Europe, the 26-year-old along with his sister, Augustina, boarded a mini-bus to the north of the country.

Picture of Augustina Imasuen — Image captionAugustina was a jovial person

Once they arrived in the city of Kano they crossed into Niger and reached the main trafficking hub of Agadez, the gateway to the Sahara.

Kelvin told me they sewed dollar notes into their clothes so that even if soldiers and border-guards robbed them they would not lose all their cash.

He saw migrants die in the desert.

"People were just collapsing," he said. "There was no food and no water. There were too many people packed into the jeeps that took us through the desert."

Despite the dangers, Kelvin and his sister pushed on, in search of a better life. Like many Nigerians they were in search of jobs and opportunities.

Finally, they reached the Libyan Coast. Europe, their dream destination, was just a boat ride away.

Media captionHow I smuggle people from Nigeria to Europe

One night, last July, hundreds of migrants were loaded onto inflatable boats on a Libyan beach.

According to Kelvin it was chaotic. Gunfire broke out after the traffickers argued. He said four migrants were shot dead.

"There were about 150 people in each boat. They were overloaded."

He was in one inflatable, his sister in another. As the boats pushed out into the darkness of the Mediterranean, it was the last time he would ever see her.

Augustina with her daughter, Lovely — Image captionAugustina drowned but left behind a young daughter called Lovely

Augustina drowned after her boat capsized. The 28-year-old nurse left behind a young daughter.

"She was a jovial person," Kelvin told me. "She loved everyone. She was making about $15 a month. It was not enough for her to pay for her daughter's school fees."

Their mother, Charity, still cannot accept her daughter is not coming back.

"I would have asked her not to go," she said. "I still don't know whether she is alive or dead."

Meanwhile, Kelvin had a lucky escape. Along with dozens of other migrants, he bobbed about in the Mediterranean Sea for four days after their engine failed.

Eventually, the Libyan coastguard rescued them. The authorities detained Kelvin before the International Organization of Migration (IOM) returned him back to Nigeria.

While Kelvin and Augustina never made it to Europe almost 40,000 Nigerians crossed the Mediterranean on rickety boats last year, the third highest number from any nation.

Europe may now be focused on migrants coming from Syria and Afghanistan but the increasing number of migrants from Nigeria and other African nations is seen as the biggest long-term challenge.

Germany unveiled what it called a Marshall Plan for Africa to support economic development in countries in a bid to slow the flow of migrants.

The fact that the policy is echoing the Marshall Plan - an American aid project that helped rebuild European nations shattered by the World War Two - highlights how seriously Germany views the problem.

But critics say Germany's plan, which promises more development aid tied to reforms such as fighting corruption and greater private sector investment on the continent, falls short of expectations.

Mother Charity with granddaughter Lovely — Image captionAugustina's daughter Lovely still asks about when her mummy coming is home

The challenges are immense. Nigeria, Africa's most populous nation, is suffering from its worst economic crisis in decades.

Its current population of 170 million is projected to double in the next 30 years meaning the problems of poverty and unemployment are likely to become more acute unless things improve radically.

"The frustration is higher now that it was before," says Osita Osemene who runs the NGO, Patriotic Citizens Initiatives, which warns migrants about the dangers of trying to reach Europe across the Sahara.

"There are lot more people now involved in recruiting migrants. They only tell them the success stories.

"As long as there is unemployment and poverty in this country the migrants won't stop."

Following his failed attempt to reach Europe, Kelvin now hopes to start up a small printing business.

But his six-year-old niece, Lovely, still asks when her mum is coming home. "I keep on telling her not to worry," said Kelvin. He cannot bring himself to tell her the truth.

Given all he has been through, he has this advice for those thinking about setting out to Europe

"I would tell them not to go by land," he said. "If they have money they should start their business here. There are too many dangers on the journey to Europe."