Nghe An, Vietnam (CNN) Amid the rice paddies and villages of central Vietnam, residents have a name for the shadowy network used to smuggle their loved ones to Europe.

Translated to English, it's called "the line," as in a factory production line.

This illicit system of moving people across borders has become so common that everyone in the hamlet of Do Thanh in Nghe An province seems to know someone who has made the journey.

"I sent my three sons," said Phan Van Thuong, a wiry 64-year-old grandfather with a crucifix tattooed on his chest. Two of them have already come back, he said, after they were arrested and deported from Britain.

"In handcuffs," he added with a broad smile.

Phan Van Thuong, 64, lives in the province of Nghe An in central Vietnam. All three of his sons went to Europe to find work.

Phan sits in his living room under a large statue of the Virgin Mary wrapped in plastic, pouring shots of rice wine for visitors into tiny glasses. The room has enormous raised ceilings, and on the walls hang several large posters depicting scenes from the New Testament and huge wedding portraits of his children.

Foreign remittances from his sons, including a third who still lives in Germany, helped pay for the construction of his three-story home. Throughout the neighborhood there are many similar two-and-three story houses, apparently built within the last decade. Some appear to sit next to the owners' original homes: single-story brick and concrete huts now crumbling and used as barns.

From the balcony, Phan points out at the surrounding rice paddies. Many of them are abandoned.

Farmers can't make enough money growing rice here any more, he said.

Instead, young people use "the line" to make the long, dangerous and expensive journey to Europe in hopes of a better life.

Point of origin

Mimi Vu, an activist based in Ho Chi Minh City who works on issues related to human trafficking and migration, said that for many young Vietnamese, the risks of seeking work overseas are worth it because they can earn far more working unauthorized in Europe than they ever would at home.

"They've had such a long tradition now of people going abroad to earn money, and sending money back home, the proof is in the houses: the villages have been transformed by new houses, motorbikes, small businesses," she said.

The district of Yen Thanh, in Nghe An province. Many families in this part of central Vietnam have close relatives who work overseas.

But a growing number of families in heavily Catholic communities like Do Thanh are reeling after the discovery of 39 bodies in a shipping container in the early hours of Wednesday morning in the British county of Essex.

British investigators are still trying to determine the identities and nationalities of the eight women and 31 men in the container, which was on the back of a truck. Each person was carrying a bag of personal belongings and many had mobile phones, which are being downloaded and forensically analyzed, police said in a statement.

Authorities in the UK initially said that they thought the dead people may have been Chinese citizens, but later backtracked as the possibility emerged that at least one of the passengers was Vietnamese. It's not clear what informed the initial assessment.

A 25-year-old man from Northern Ireland is due to appear in court on Monday charged with 39 counts of manslaughter, conspiracy to traffic people, conspiracy to assist unlawful immigration, and money laundering. It is unclear how the suspect intends to plead, and his lawyer did not respond to CNN requests for comment. Three other people arrested have been released on bail.

Le Minh Tuan and two of his grandchildren. Their father - Le's son - is believed to have died as he tried to make his way to the UK.

A family in mourning

A stone's throw from Phan Van Thuong's three-story house, 58-year-old Le Minh Tuan is receiving visitors who burn incense in front of a shrine dedicated to his son.

Le is convinced his son, Le Van Ha, died in the Essex container.

"On October 21st, he called for the last time to say he's preparing to get into a truck (to the United Kingdom)," the elder Le said.

Since then, Le said his son's phone has gone dead. Meanwhile, he said he's heard from sources, whom he refuses to reveal, that his son was on that final, fatal trip.

Even though the Vietnamese government has only just begun collecting DNA samples from families to begin the process of identifying victims, Le is calling on the British and Vietnamese governments to send his son's body back so the family can hold a proper funeral.

Le Van Ha's wife, Tran Thi Ha, waits to hear whether her husband's body has been identified.

The younger Le was 30 years old, married and the father of a young boy when he left Vietnam last July, flying first to Malaysia before traveling on to Turkey and Greece, his father said.

"His friends in this community invited him to go abroad for a better life," Le added. "He said he would go to the United Kingdom to earn money to build a new home. He was very determined."

To pay "the line" a smuggling fee of 700 million Vietnamese dong, or roughly $30,000, the elder Le had to get a bank loan. He also put up his land and his house as collateral.

When the younger Le reached Greece, his wife back in Vietnam gave birth to a second son.

Now 10 weeks old, chubby-cheeked little Le Nhat Manh sits cradled in his grandfather's lap as the elder man sobs.

"I lost my son. I lost my money and I don't know how to raise these children," he said, his eyes red with tears.

Shrine to Le Van Ha in his family home.

Unanswered calls

Five minutes' drive away, Dang Thi Ha is holding out hope that her son survived the cross-channel journey.

He called early last week and asked relatives to light incense for good luck before boarding a truck to Britain. He hasn't been heard from in days.

Dang said 28-year-old Vo Ngoc Nam left Vietnam last year legally with a contract to work in a factory in Romania.

She said he quit the job when he was paid half the salary he was promised. The family paid 200 million Vietnamese dong, or around $8,500, for Vo to go to Germany where he ended up working in construction.

In the hopes of finding a better opportunity, his family said Vo planned to get smuggled to the United Kingdom using a "high quality line."

"I'm angry at the line," said Vo's brother-in-law Nguyen Trong Tam. "They guaranteed 100% success."

'The most important thing is life'

The United Kingdom is a popular destination for unauthorized Vietnamese workers.

In 2018, more than 700 suspected cases of modern slavery and human trafficking were reported from that country alone, the second highest foreign source behind Albania, according to the UK's National Crime Agency, though it notes that not all suspected cases are ultimately assessed as involving modern slavery.

Most of the Vietnamese nationals were suspected victims of labor exploitation, according to government figures.

Last November, the British and Vietnamese governments signed a memorandum of understanding on human trafficking, to share more intelligence and work together to support victims. "This close collaboration will be a powerful weapon in the fight against modern slavery," British Home Secretary Sajid Javid said at the time.

A neighbor of the grieving Le family is convinced the Essex disaster will have a lasting impact on his community.

"After this, no parent will allow their children to go work overseas. Because now it's so risky," said Ho Van Thanh, who runs a small roadside shop.

"Money is important. But the most important thing is people, life."