On the morning of April 12, the farmworker woke up struggling to breathe and delirious with fever.

Jiaai Zeng had spent the past month working nonstop at a marijuana farm in Oklahoma run by fellow Chinese immigrants. The job was brutal, the 57-year-old had told relatives in New York. He said his bosses made him labor up to 15 hours a day in the blast-furnace heat of a greenhouse. He was feeling awful even after a visit to the doctor, so he planned to return to New York that evening for medical treatment.

At 9:38 a.m., Zeng sent an audio message to a cousin in Manhattan’s Chinatown. In an agonized whisper, he asked her to buy a bag of oranges for when he arrived.

“I don’t want to eat anything,” he said, speaking a dialect of Fujian province. “I just want to take a look at oranges and see if I’ll have an appetite.”

About an hour later, Zeng was unconscious and had no pulse when three people from the farm drove him to a nearby hospital. They dropped him off and left in a hurry while doctors were trying to revive him, according to a hospital report.

By 11:05 a.m., Zeng was dead.

“This death is not normal,” said his nephew, Westin Zeng, in an interview with ProPublica and The Frontier. “He lives there for a little bit over 30 days: from a healthy person to a dead person. It doesn’t make sense to me. … In my mind, there’s a logical link from his work to his illness, and from his illness to how they handle that, and a link to his death.”

The farmworker’s story gives a glimpse into the harsh and often abusive conditions endured by the tens of thousands of Chinese immigrants who have quietly become the backbone of many U.S. marijuana operations.

“It is one of the most deplorable parts of what we see in this industry,” said Donnie Anderson, the director of the Oklahoma Bureau of Narcotics, who met with Zeng’s relatives and ordered an investigation.

Cannabis farms have boomed in states that have passed medical and recreational marijuana laws. But when voters in Oklahoma approved a law allowing the cultivation of medical marijuana in 2018, legislators didn’t develop corresponding regulations to protect employees. Oklahoma’s historically weak labor enforcement system leaves the protection of workers largely to the federal government. And the U.S. Department of Labor has limited oversight because marijuana is illegal at the national level.

As a result, workers who are already isolated by language and culture have found themselves largely at the mercy of their employers, often criminals who rely on Chinese immigrant labor. As ProPublica and The Frontier have reported, Chinese mafias — some with suspected ties to the Chinese government — have taken advantage of state-level legalization to dominate a nationwide black market for marijuana.

How Chinese Organized Crime Is Dominating America’s Illegal Marijuana Market

During raids, inspections and investigations at more than a thousand farms over the past five years, Oklahoma law enforcement officers, fire marshals, federal labor inspectors and other officials have encountered a litany of abuses: bosses threaten and beat workers, sexually assault them, steal their wages, confiscate their IDs, restrict their movements and force them to work in dangerous heat with noxious chemicals and pesticides. Wrongdoing is rampant at many Chinese-owned farms, where immigrants are often so fearful of their employers and the authorities that they do not cooperate with investigations, according to law enforcement officials, court cases, human rights advocates and workers.

The mistreatment and squalid conditions are the hallmarks of human trafficking, said Craig Williams, the chief agent of the marijuana and human trafficking sections of the Oklahoma Bureau of Narcotics.

“It’s hard to convey what it’s like until you’re standing there, looking at the people, looking at the environment, smelling the environment, seeing what they’re living in,” Williams said. “Your heart goes out to them like, ‘This is just wrong.’”

While problems are particularly bad in Oklahoma, studies and media reports have detailed similar risks nationwide to laborers, many of them recent arrivals who crossed the Mexican border illegally. Exploitation of Chinese immigrants pervades the marijuana underworld from California to New Mexico to Maine, according to interviews and court cases.

And even overseas, authorities have found patterns of mistreatment at Chinese-run marijuana sites from Chile to Ireland.

“These are people living in a situation of semi-slavery,” said a police official in Spain, a center of illegal marijuana cultivation in Europe, who spoke on the condition of anonymity for safety reasons. “They are locked up 24 hours a day. They don’t know what country they live in. They don’t have contact with the outside world.”

During raids in 2021 on cannabis plantations hidden in warehouses near Barcelona, Spain, police freed 10 immigrants from Fujian whom gangsters had forced to work to pay off smuggling debts of up to $35,000. The drug traffickers locked the workers in the dirty, windowless buildings, making them sleep on mattresses on the floor. Some of the victims spent up to a year in captivity, police said.

“Everyone has a different story, but the bottom line is that they have not escaped the darkness of China,” said Ju Ma, a Chinese human rights advocate who runs a migrant shelter in New York that has aided marijuana workers.

In the Zeng case, the federal Occupational Safety and Health Administration and the Oklahoma Bureau of Narcotics are investigating. The Office of the Chief Medical Examiner recently concluded that the cause of the farmworker’s death was pneumonia.

“They are making so much money in the marijuana industry, but they are treating the workers like slaves,” Westin Zeng said. “I want to find out everything that happened and get justice for my family.”

The farm’s owners have not been sanctioned or charged with a crime in relation to the case. Jeffrey Box, a lawyer for one of them, rejected the Zeng family’s allegations that neglect and harsh working conditions played roles in the farmworker’s death.

Official data and reports on labor in the marijuana industry are sparse, and Chinese workers rarely talk about their experiences. To report this story, ProPublica and The Frontier interviewed several dozen current and former law enforcement officials in the United States and overseas, other government officials, farmworkers, human rights advocates, lawyers and others. Reporters also reviewed court documents, medical files, government reports and social media posts in English, Chinese and Spanish.

The reporting reveals a saga of despair that remains largely out of sight for the U.S. public. Zeng’s case is rare because his family has spoken out. Many Chinese immigrants enter the nation’s marijuana industry hoping to plant the seeds of new lives, but they end up suffering in silence.

“If they go missing, no one’s going to report anything,” Williams said. “I sincerely wonder how many people are buried on illegal marijuana grows.”

The Journey

Zeng was born in a village in Yongtai County, Fujian. His nephew remembers him departing at dawn to cultivate rice and plum trees, and returning after dark.

“If people were carrying two baskets of stuff, he carried four,” said Westin Zeng, now a 32-year-old business consultant in New York.

A father of two, Zeng also did itinerant manual labor in Shanghai and other cities to support his family, including his father and a grandson who are both disabled. In 2021, he converted to Christianity (his U.S. relatives are Christians), which caused police in his hometown to harass him, according to an account he later wrote for a U.S. immigration court. At the same time, the pandemic was worsening China’s economic woes and the hardships of its working people.

Zeng decided to leave. His U.S. relatives lent him about $65,000 for the smuggler’s fee. The money included a payoff to expedite issuance of a passport by Chinese officials in Fujian, a coastal province whose longtime smuggling underworld intertwines with official corruption. Zeng traveled via Bolivia and Mexico, climbing the border fence into San Diego in December 2022. After Border Patrol agents arrested him, he requested political asylum and was released.

He arrived during a multiyear surge of immigration from China. In the first eight months of the 2024 fiscal year, the U.S. Border Patrol apprehended around 31,000 Chinese nationals illegally crossing the southwest border. That’s over 15 times more than the entire 2019 fiscal year.

Some Chinese border-crossers find work in marijuana operations after they arrive. Others are smuggled across the globe specifically to work in the cannabis industry.

A former senior Drug Enforcement Administration official said the agency has learned about these clandestine labor pipelines from informants and a jailed high-level human trafficker and money launderer.

“The word goes out: We need more manpower for all these marijuana farms,” said Christopher Urben, who is now a managing director at the global investigations firm Nardello & Co. “The same networks are involved in weed, money laundering and human smuggling.”

Blackwell

When Zeng reached New York in early 2023, he gave thanks at a Fujianese church in Chinatown and became a regular worshipper.

“He was surprised how much people were willing to support him,” Westin Zeng said. “He was really touched. He told my father it’s totally different here.”

Zeng first worked at a restaurant and then, at the suggestion of a cousin employed in the marijuana industry in Oklahoma, spent a month last summer working at a marijuana farm there. He had no complaints about that experience, his family said. He saved money to send to family in China and to pay off debts incurred by his overseas journey.

Back in New York, Zeng, who had just gotten Medicaid insurance coverage, underwent a medical checkup in early March that did not find serious ailments, according to the doctor who examined him, medical documents and his family.

On March 7, Zeng returned to Oklahoma to work at a farm in the small town of Blackwell, near the Kansas state line. Photos and public records show the 65-acre lot had six greenhouses and nine indoor grow houses and, according to Zeng’s family, the farm employed about 13 workers. The metal fence displayed signs depicting a pistol above the warning “Lawful Concealed Carry Permitted on Premises.”

Zeng earned about $4,500 a month for trimming plants, spreading fertilizer and doing pest control, his family said. His shift began at 7 a.m. and lasted as late as 10 p.m., with no days off. He slept in a cubicle in a partitioned room in the red-roofed main house.

In calls to relatives, Zeng sounded unhappy. Although his bosses and co-workers were also Fujianese, they mistreated him because they were from another county with a different dialect, he told his relatives. The meals were meager, workers were quitting because of the intense pace and the plastic-covered, dome-shaped greenhouses were infernally hot, he told them.

“He was complaining to my aunt that he had to work almost naked because it was too hot in there,” Westin Zeng said. “The only way to cool down was to spray himself with water.”

Investigators have documented heat reaching over 120 degrees at some farms, Williams said. During raids, agents routinely cut the sides out of the greenhouses to dissipate the heat and fumes from chemicals. Agents wear oxygen monitors because farmers pump in CO2 to enhance the growth of plants, a practice that depletes oxygen levels without agents, or laborers, realizing it.

“I worry about our agents’ health all the time,” Williams said. “And those workers are living in it.”

Government and academic studies have found that heat and humidity in the greenhouses can promote bacterial growth and cause heat stress, and that chemicals, gasses and other substances at marijuana farms can result in ailments ranging from allergies to fatal asthma. Other research shows that extended time in excess heat can cause human organs to shut down.

Fires and explosions are another hazard. And many farmers use toxic pesticides smuggled from China or across the Mexican border that have made workers sick in California, officials said.

The extent of such hazards at the Blackwell farm is not clear. Zeng told his family that he sometimes wore a mask because of the smell of chemicals and marijuana, his relatives said.

Box, the lawyer representing an owner of the farm, disputed the family’s allegations about extreme heat and other conditions at the farm.

Around April 9, Zeng fell ill. Someone from the farm took him to a doctor in Oklahoma City on April 10. The doctor diagnosed cystitis and a urinary tract infection — conditions that research shows can be exacerbated by heat stress — and prescribed an antibiotic, according to medical records and the relatives. (The doctor declined a request for comment.)

That night, Zeng talked to his family about flying back to New York, where his insurance would help cover further treatment.

“I want to give it a few days, wait until I get better, then leave,” he said in an audio message.

Despite the antibiotic, his condition deteriorated. His bosses bought him a plane ticket to New York for the afternoon of April 12, his family said. That morning, he recorded the audio message to his cousin.

“You can hear he was dying,” Westin Zeng said.

At 10:35 a.m., an hour after Zeng sent the message, a minivan pulled up to the emergency room at Stillwater Medical Center-Blackwell. Nurses found Zeng slumped unconscious wrapped in a blanket. They began CPR, put him on a stretcher and rushed him inside, according to the hospital report.

The woman and two men who brought him from the farm claimed they did not speak English and provided little information “other than the patient’s date of birth and his name,” the report says.

Using a Mandarin-speaking phone interpreter, the nurses got a few answers from the woman, who identified herself only as Stella. She “was not very forthcoming” and asked several times when she could leave, the report says. She denied knowing Zeng but explained that he worked at a marijuana farm, had been sick two or three days and had seen a doctor, the report says.

Stella “left with the other two males,” the report says. “CPR continued.”

Doctors pronounced Zeng dead a half hour after his arrival. Tests revealed he had sepsis and pneumonia, the report says. A hospital spokesperson declined to comment.

“Selling Hope”

Zeng died at a time when Oklahoma is confronting the dark side of its rush into the marijuana frontier.

In 2018, voters passed the ballot petition that legalized medical marijuana with 56% of the vote. The petition written by citizens included virtually no regulations. The following year, the state Legislature approved several regulations protecting consumer access to medical marijuana, but it did not address the health and safety of the marijuana workers.

At the peak of the billion-dollar marijuana boom in 2022, the state had almost 10,000 cannabis farms, which have an estimated average workforce of 15 to 20 employees per site. Although a crackdown on black market marijuana trafficking has cut the number of farms, authorities still come across abusive, squalid and unsafe workplaces.

Problems are endemic at Chinese-owned farms engaged in illicit activity, officials said. Workers often tell investigators their bosses promised to pay them at harvest, then claimed the harvest wasn’t big enough. Owners sometimes offer new hires an eventual cut of the profits, and even entice them to invest hard-won savings in the ventures, then rip them off, according to law enforcement officials and workers.

“We see promised pay that hasn’t been delivered on very frequently now,” Williams said. “They think they just have to work in a really bad environment for a while and think it’s going to pay off at the end. They don’t realize they’re working on an illegal grow. And that the work they’ve done, they’re never going to get paid for anyway. To some degree, they’re selling hope.”

In a rare workplace enforcement case in 2021, the Oklahoma Department of Labor judged that four Chinese employees were owed a combined total of nearly $57,000 in unpaid wages and damages after investigators found they were not paid for months of intense physical labor at a marijuana farm in southern Oklahoma.

“We were overworked,” said Yulin Zheng through an interpreter in an interview with ProPublica and The Frontier. Nearly 50 employees worked up to 14 hours a day, no days off, and lived in trailers without air conditioning, she said.

Zheng and her husband, Chang Qin Jiang, both in their late 60s, took jobs in Oklahoma after someone told them cannabis was a lucrative industry. They were each paid $4,000 in cash the first month. But the next month, a boss told them he didn’t have the money, according to screenshots of text messages they included in a complaint to the Labor Department.

“I’ll pay the wage in several days, probably next week,” he said in a text message. “Believe me!”

The cash never came. Months later, he told them they could make money if they bought one of the farm’s greenhouses to grow and sell marijuana themselves, the couple said.

“It was like a chicken game,” Zheng said. “They were trying to keep as much money as possible.”

The employer eventually abandoned the farm, leaving many workers without food or transportation, according to the couple and court documents. The couple’s son in California drove to Oklahoma and helped them file the successful claim.

Later, an owner of the farm tried to apply for bankruptcy, but a court found she had not disclosed hundreds of thousands of dollars in income from marijuana ventures, court documents say. Public records also show that the phone number for the farm belongs to the Chinese owner of a furniture store in Oklahoma City that the FBI raided last year in an investigation that led to three other people being convicted. Investigators found that the store was being used as a front for a criminal network that trafficked marijuana to the East Coast using fake Amazon delivery vehicles.

Workers at other farms have recounted their struggles in Chinese-language blog posts. In 2021, an electrician at a farm near Maramec, Oklahoma, alleged that his employer threatened to “have our legs broken” when he and his wife asked for months of wages they were never paid. Another woman at the same farm described how a boss “grabbed an iron bar and a gun” to menace her during a confrontation over unpaid salary. Court documents show the farm was later raided and the owner convicted on drug charges.

Scams are common in other states as well, according to interviews and court files.

“What we see is Chinese nationals who are either here legally … or were smuggled in across the Mexican border and are forced into labor, or more often tricked into labor,” said Kevin McInerney, a commander at the California Department of Cannabis Control.

Agents in Southern California are investigating the recent case of a woman who invested $10,000 to work at a marijuana farm in exchange for a small monthly wage and an eventual cut of the profits. After she toiled in awful conditions, the employers refused to pay her first month’s salary. She stopped working in protest, so they drove her out into the desert and abandoned her at a gas station, officials said.

Pervasive criminality makes the marijuana business “inherently more violent” than other industries, said Whitney Anderson, who directs The Dragonfly Home, a shelter for victims of human trafficking in Oklahoma City.

Workers in Oklahoma have suffered beatings and even died in robberies and shootings. In one case, an employee told police her boss grabbed her by the hair, fired shots near her head and threatened to kill her and her daughter, according to court documents.

Sex crimes are also a danger. A 42-year-old former supervisor at a cannabis farm in Noble County is facing charges of rape and sexual battery after he allegedly assaulted an employee in her sleeping quarters in 2022, court documents say. He had previously tried to assault her at work by slipping a dose of ketamine into her drinking water to incapacitate her, but a co-worker intervened, the documents say. The former supervisor has pleaded not guilty and is awaiting trial.

“I’m so scared [he] will take revenge on me, my daughter, or family,” the woman wrote in a request for a protective order. “I have to live in fear every single day.”

And in another dramatic incident in 2021, a Chinese worker in Garvin County escaped from a marijuana farm and ran to a nearby house, where he banged on the door screaming for help. A man and a woman chased him down and tried to drag him back across the road, according to 911 call transcripts, court records and interviews.

“They had a big old fight in my front yard,” Diann Skinner, who lives in the house, said in an interview. “They’d tackle him, he’d get up and take off and they’d tackle him again.”

Frightened neighbors and passing drivers called police, who arrived as the assailants wrestled with the escaped worker. The 37-year-old victim told officers that the woman and two men had held him against his will for three months and forced him to work. He was “extremely scared” of his captors and “believed they would try to kill him,” a police report said.

Police found 1,500 pounds of illegal marijuana, $32,000 in cash and two pistols in the run-down property, which served as a processing depot for Chinese-owned farms involved in illicit trafficking, according to court documents and interviews.

Prosecutors filed charges of kidnapping and drug trafficking against the suspects. But the victim quickly left the state, making it impossible to pursue the kidnapping charge. The two men were convicted of the drug offenses and sentenced to two years in prison. The charges against the woman were dropped.

Fifty Thousand Dollars

The day after Zeng’s death, his distraught nephew hurried to Oklahoma City and met with a man and four women from the farm. They had a tense conversation in the lobby of an apartment building, he said.

“They said, ‘We did everything right,’” Westin Zeng said. “The attitude of these people to me was, the whole tone of the conversation was, ‘It was your uncle’s fault.’”

The group did not give their names and offered to pay $50,000 if the family kept silent, Westin alleges. He said he refused.

ProPublica and The Frontier used photos, social media, public records and other sources to identify the owner of the farm, Xiuna Chen. Westin Zeng recognized her as one of the people at the meeting.

Chen has not been charged with any crime. But public records show that her Blackwell farm has multiple ties to another farm that was recently raided by the Oklahoma Organized Crime Task Force, which led to six indictments. The defendants have pleaded not guilty.

Chen referred reporters to Box, her lawyer, who accused the dead worker’s family of trying to “shake down” his client “for a ton of money.”

Another woman that Westin Zeng recognized from the meeting is Zhixin Liu, who on social media goes by Stella — the name given by the woman who brought Jiaai Zeng to the hospital. Liu’s phone is on the marijuana license for the Blackwell farm, and she is identified as its owner on a report by firefighters who responded to a fire there in April.

In 2022, Liu established a corporation with Zenith Top LLC, an Oklahoma City firm that has been raided for allegedly setting up illegal marijuana ventures, public records show. She listed her address as a house that belongs to a suspected owner of Zenith Top, according to public records and court documents. The owners of the firm have not been charged, though agents have executed search warrants and initiated money forfeiture actions against them that are awaiting trial.

Liu declined requests for comment.

While in Oklahoma, Westin Zeng met with the state anti-drug director and an official at OSHA. Officials at both agencies told ProPublica and The Frontier that they are investigating the farmworker’s death and the Blackwell farm.

The family’s engagement with authorities is unusual. Many workers who feel they have been victims of wrongdoing don’t have contacts in the U.S. or their relatives are fearful and speak little English, officials said.

Last year, the state narcotics bureau succeeded in building a human trafficking prosecution in a grim case: The accused ringleaders forced women to work as prostitutes at a brothel catering to owners and managers of Chinese-owned marijuana farms, flying the women to Oklahoma City from New York, according to court documents.

In general, though, the reluctance and elusiveness of victims discourage authorities from filing charges of human trafficking or workplace abuses. They focus instead on drug-related offenses by the owners.

The clash between state and federal laws combined with weak regulation make workers in Oklahoma especially vulnerable.

Oklahoma leaves regulation of workplace safety to OSHA, but the agency does not proactively monitor marijuana worksites in Oklahoma, and it only investigates in extreme cases such as job-related injuries or deaths, officials said. Because marijuana remains illegal at the federal level, OSHA has not developed specific workplace safety regulations for the cannabis industry, and relies mostly on the agency’s general duty clause, which covers all employers, for enforcement.

By contrast, in California, which has its own state-level workplace safety agency, a state task force requires owners of marijuana operations to take a training course and create a written injury and illness program. Even owners of illegal growing sites are subject to such rules, a spokesperson for the California Department of Industrial Relations said.

Oklahoma leaders say they are trying hard to overcome a bureaucratic limbo. The state labor commissioner, Leslie Osborn, said in an interview that the heads of agencies met last year “to really knock out who is responsible for what. And there is not a lot of clarity.”

“We let this flourish like a black market,” Osborn said, “and now we’re kind of behind the eight ball.”