In the spring of 2015, 18-year-old Yiran “Camellia” Liu stood outside an ice cream parlor in Rowland Heights, Calif., and waited. She was there to settle a minor dispute with another teenage girl — about an unpaid dinner bill, of all things.

The girl arrived accompanied by a handful of others. Like Liu, they were all “parachute kids,” Chinese high schoolers who had come to the U.S. to study — paying steep international tuition fees —  while their parents remained overseas. They clung to one another out of a sense of shared isolation.

But on that day, as afternoon turned to night, this bond did little to protect Liu.

At the ice cream shop and later at a nearby park, she was brutalized for more than five hours. According to court testimony cited by the Los Angeles Times and the San Gabriel Valley Tribune, the other teenagers forced her to kneel and wipe cigarette butts and ice cream smears off the floor with her bare hands. They also slapped and kicked her.

“Can you just get the hell out of Los Angeles?” one girl asked Liu. “No, you know, you shouldn’t — you should not be leaving Los Angeles because if you do, then it will be no fun for us. We can’t hit you anymore.”

After taking Liu’s cellphone and car keys, the group drove her to Rowland Heights Park in her own car and forced her to strip before continuing to beat her. While Liu was naked, they burned her nipples, hip and chest with cigarettes. They cut her hair and made her eat it.

When it was all over, they asked Liu to give three of the girls a ride back, and she did, because she was too scared to do anything else.

Wednesday, three of the assailants — Xinlei “John” Zhang, Yuhan “Coco” Yang and Yunyao “Helen” Zhai, all 19 — were sentenced on counts of kidnapping and assault by means of force likely to produce great bodily injury.

Zhang was sentenced to six years in California state prison, Yang to 10 years and Zhai to 13. The lengths of the sentences were determined by each person’s degree of involvement. Two days before ambushing Liu, Zhai and Zhang had also assaulted a 16-year-old girl in Rowland Heights. All three had previously pleaded no contest to the charges against them, the Los Angeles County District Attorney’s Office said in a press release Wednesday.

Previously, a 16-year-old girl and 17-year-old boy were sentenced to juvenile camp for the beatings, while Zheng Lu, 20, is awaiting trial on the more severe charge of torture. Authorities believe that the other attackers have fled the country.

During the initial hearings, California Superior Court Judge Thomas C. Falls likened the case to “Lord of the Flies,” a 1954 novel about British school boys stranded on an otherwise uninhabited island, isolated from civilization and bereft of adult supervision.

The result is utter anarchy, violence and destruction.

While extreme, Falls’s comparison was an apt one: both Liu and her attackers were living an ocean away from their immediate families, in an environment largely foreign to them. America was their island.

The “parachute kid” phenomenon dates back to the 1980s, according to psychologists Yuying Tsong and Yuli Liu. They are defined as “underaged foreign students who are sent to live and study in the United States without their parents…They can be as young as 8 years old, but the majority are between the ages of 13 and 17 years old.”

Tsong and Liu wrote in a 2009 journal article called “Parachute Kids and Astronaut Families” that while affluent Asian parents often sent their adolescent kids abroad in the hopes of bolstering their education, these good intentions could backfire as the teenagers struggled in unfamiliar surroundings.

Many parachute kids succeed academically, but they are also more likely to experience depression and experiment with alcohol and drugs. Meanwhile, their parents may be wracked with guilt over the separation, and attempt to compensate by showering the children with expensive gifts.

Living situations vary: some reside with relatives, others in group houses with other international students, others with “homestays” (surrogate guardians who provide room and board, for a price). As Tsong and Liu learned, however, the kids still felt overwhelmingly alone.

Perhaps most daunting of all, they are responsible for managing their own free time, a perilous task for any teenager.

“Three to ten is a long time to be on one’s own,” one former parachute kid told psychologist Min Zhou in 1998. “I didn’t like it at all. I got bored, turned on the TV, played video games, ate junk food…Good thing that none of my friends were in gangs.”

The Rowland Heights case has invited scrutiny of this solitary existence, prompting communities in California and China to reconsider the ideal of the parachute kid.

“I’m sure they suffer from loneliness,” Rayford Fountain, Yang’s attorney, said, according to the LA Times. “So they bond with other kids in the small Chinese circles with no supervision, no one to turn to for assistance. So these things can get out of control.”

Some of the attackers were students at Oxford School, a private high school comprised of nothing more than a handful of portable classrooms behind a strip mall, according to the LA Times.

The school has 140 international students, mostly from China, who pay around $12,000 in tuition annually.

At the sentencing on Thursday, Zhai, Zhang and Yai shielded their faces from reporters. The case has attracted significant attention in their native China, where many applauded the punishment.

“I’ve heard that I’m hated here and in China, and I probably deserve to be viewed that way,” Zhai said in a statement read by her attorney, according to reports from the Times and the San Gabriel Valley Tribune. “I hope [the victims] do not carry the wounds from what I did for the rest of their lives.”

She added that she “owes everything” to her parents: “They sent me to the U.S. for a better life and a fuller education. Along with that came a lot of freedom, in fact too much freedom … Here, I became lonely and lost. I didn’t tell my parents because I didn’t want them to worry about me.

The father of Zhang, who lives in the southern Chinese city of Shenzhen, spoke to reporters in Mandarin before the sentencing.

A laborer-turned-businessman, he expressed regret about sending his son abroad.

“If he’d never left my side,” Zhang told the LA Times, “that would have been better.”