'It eats away at my body': The human cost of S Korea's ultra-convenient overnight deliveries

A week before her son died Park Mi-suk asked him to quit his job.

For more than a year, the 27-year-old had been working overnight shifts at a warehouse for the country's largest online retailer, Coupang. He steered pallet movers with stacks of plastic bins and cardboard boxes across the sprawling space.

In that time, Park says, her son lost 15kg and often complained of how tired he was.

But Jang Deok-jun refused to quit. He compared his job to being on a seesaw: if he stepped down, his co-workers would struggle to keep going.

The following week, Park found him unconscious and hunched over in the bath.

"We pulled him out and performed first aid. We rushed him to hospital, where they declared him dead."

Jang died of a heart attack. The state-run insurer that covers healthcare for workers, Comwel, blamed his death on overwork following an investigation.

Park wishes she had noticed Jang's exhaustion sooner. "I didn't pay attention to my son's words, so I lost my son. But I hope others won't repeat the same mistake."

Jang died in 2020 but six years on, Park is still fighting to end what she believes is the reason for his death: night-time deliveries.

Jang died as deliveries surged during the pandemic, which was often cited to explain his workload.

But the working conditions for warehouse and delivery workers have been the subject of a growing national debate, with their union claiming that suspected deaths from overwork have continued.

Night-time deliveries have become ubiquitous in hyper-connected South Korea, where shoppers are guaranteed delivery by 07:00 for orders placed before midnight. This convenience is thanks to a huge overnight workforce, from warehouse workers like Jang to delivery drivers.

Several companies compete to offer speedy, cheap deliveries but the biggest is Coupang.

Founded by a Korean-American, it became synonymous with online shopping in South Korea after 2015, when it started offering fresh produce overnight. It has grown to have an unrivalled network of warehouses and delivery trucks, with nearly 100,000 employees across the business.

But increasingly, this industry is under scrutiny.

Between 2020 and May 2026, Comwel ruled that 46 warehouse and delivery workers, including Jang, died of a stroke or heart disease that count as work-related deaths. Jang aside, it's unclear how many of them worked overnight shifts.

Comwel did not say how many of these cases were also investigated for the role of overwork, which only happens if the family asks for it in their claim. And not every case is referred to Comwel in the first place, so the data can be patchy.

Previously Comwel data suggested that day-time delivery workers died of overwork and accidents at a higher rate than those who work overnight.

But that is now questioned by those who say night-time deliveries are expanding fast, and there is not enough data to fully document their impact yet. The workers' union also argues that the latter is more harmful to health in the long-term.

Night-time work is a probable cause of cancer globally, according to the UN's cancer research body. "Not only that, evidence has been accumulating that it also raises the risk of cardiovascular diseases, diabetes and mental illness," says Kang Mo-yeol, professor of occupational medicine at the Catholic University of Korea.

South Korea doesn't limit overnight working hours, unlike in the UK, where night-time delivery drivers cannot work more than 10 out of 24 hours.

The Korean delivery workers' union called for a ban on overnight deliveries in 2025, but the union for Coupang's drivers says nearly all of their members prefer working at night.

Some have children, elderly or ill family members to care for during the day and, more importantly, it pays better.

"I can't do this for life because it eats away at my body," says Kim, a Coupang driver on a sub-contract, who did not want to share his real name. But he adds that his monthly salary of around 7m won ($4,600; £3,430) - nearly double the national average - makes it worth it.

When the BBC met him at 22:00, he had already loaded his truck for the first round of deliveries.

Driving through the narrow streets of Incheon city, west of the capital Seoul, he explains that he works from 21:00 to 07:00, five to six days a week.

His schedule does not allow for a break. Every time the truck stops, he runs, package in hand. Nearly all drivers are paid by the number of packages they deliver and if they fail to make all deliveries by 07:00, they risk losing their "territory" to a competitor, he says.

At first, his pregnant wife was scared he might fall asleep at the wheel. But he is used to it now, he insists, and he finds it easier to navigate the night's empty streets.

"We choose to deliver overnight for the money," Kim says. The way he sees it, those who are saying overnight deliveries should stop because they affect his health are ignoring the choice he has made.

But men like Kim are becoming invisible, Jang's mother Park says, as the demand for fast deliveries grows, normalising the industry.

Park spoke to the BBC outside Coupang's headquarters in Seoul's office district of Songpa. Standing alone in front of the gate, she told staff streaming out for lunch to remember her son and others like him. Few paid attention.

Park says one of the challenges is how hard it is to hold employers accountable in cases like Jang's.

She says it was on her to prove that her son had died from overwork, and Coupang was obligated to provide records, including security camera footage, to Comwel, but not her. After months of leaning on lawmakers and government agencies, she received Jang's work log and relevant CCTV footage.

In the months before his death, Jang's working hours met the bar for how South Korean law defines deaths related to overwork: heart attacks or brain strokes after an average 60-hour-week over 12 weeks, or 64 hours a week in the four weeks leading up to death.

Jang's overnight hours counted 30% more towards the calculation, according to Comwel's rules.

As Park continued her fight, local media published what Coupang's former chief privacy officer claimed was a conversation with Chairman Bom Kim.

In the leaked chat, Kim orders the executive to remove mentions of Jang "working hard" from internal reports: a phrase several employees used to describe Jang's final shift. Coupang called it a "groundless" claim by a disgruntled former executive.

But the union accused the firm of covering up evidence and filed a criminal complaint. The police launched an investigation into Coupang in December 2025. Coupang denies the accusation, saying it had submitted everything that was requested and had fully cooperated with Comwel's investigation.

By then, another high-profile case was in the headlines. Oh Seung-yong, 34, died after crashing his truck into a pole during a delivery run. It was an "occupational death", or work played a role, Comwel ruled.

Oh's sister told parliament his work log showed that he had been working six days a week, more than 11 hours a day, and mostly at night. According to her, when their father had died days earlier, Oh delivered orders for another four hours before coming to hospital. He worked for a logistics company contracted by Coupang.

Coupang says it restricts its employees to working for under 52 hours and gives sub-contracted drivers the full weekend off every two weeks. But the union alleges that this was not enforced by Oh's employer.

The firm added that it fully pays for health check-ups for direct employees and sub-contracted drivers, and "has never had a single industrial accident death, which is the best safety record in the entire global logistics industry".

Coupang CEO Harold Rogers was summoned to parliament in December 2025 over the deaths of Jang and Oh, as well as to answer for a recent data breach at his firm, involving 37.5 million users. The country's largest ever breach, it earned them a record $410m fine.

During the televised hearing, Park demanded that Coupang's Chairman Kim be held accountable for her son's death, while Oh's sister asked for an apology from Rogers. He said he was "sorry" and offered his "deepest condolences". When Oh's sister pressed further, he was silent.

The investigation into Coupang has also raised key questions for President Lee Jae Myung, who has a disability in his left arm from an old injury at a factory. He made it one of his priorities to reduce workplace injuries and deaths.

Stories like Jang's and Oh's resonate deeply in South Korea, where gruelling work hours are no anomaly. It has one of the highest rates of workplace deaths among developed countries, a grim statistic it has been trying to improve for decades.

The government has capped weekly work hours at 52 and passed a law to jail executives for negligence leading to workplace deaths.

To break Coupang's stranglehold, the governing party even proposed relaxing existing restrictions so more retailers can deliver overnight. But the bill angered unions, activists and Park, who say the challenge goes beyond Coupang.

"I've been haunting the streets since my son died," Park says.

Because of all the time spent fighting for compensation and answers, she was forced to close her furniture-making business. She could no longer afford to live in her old home and moved to a rental apartment in Daegu city.

She has kept all of Jang's belongings, including his collection of action figures. They sit in a box in her new apartment.

She isn't ready to say goodbye yet, or to give up her fight.

Recalling how Jang compared his work to riding a seesaw, where he held down one end, she says she sees it differently now.

Jang and tens of thousands of workers like him are on one side for the convenience of the consumers on the other end, she says.

"I hope we don't become a society where we close our eyes to others' sacrifice for a little convenience."