Advocates have sounded the alarm after a teenager detained in a maximum-security adult prison in Western Australia required medical treatment after self-harming.
The teenager was taken to hospital this week from a facility in Perth's Casuarina prison, Guardian Australia has confirmed.
Another child at the unit had made threats to self-harm but did not do so.
The teenage boy, detained at the purpose-built juvenile wing at the prison, was taken to the hospital and has since been transferred back to the prison.
Last month the WA government transferred 17 young people, some as young as 14, from Perth's Banksia Hill juvenile detention centre to the adult jail after "escalating" disruptions from young people.
The project director of the National Suicide Prevention and Trauma Recovery Project, Megan Krakouer, said the incident was "alarming" and a sign of deteriorating mental health among the young detainees at the prison.
"I am gravely concerned for these children," Krakouer said. "I'm worried there will be a suicide involving a young person for the first time ever in a Western Australian prison."
Krakouer, who supports vulnerable and at-risk families as well as those within the justice system, said the families of the detainees were often traumatised.
"I know these kids, I know their families and the trauma that they have been through, and unless we see a trauma-informed restorative justice approach, we will see a death," she said.
WA's children and young person commissioner, Jacqueline McGowan-Jones, was alerted to the incident shortly after it happened and said it raised serious concerns.
She said self-harming, threats of self-harm and the damage of cells were an indication of distress and anger.
"These are kids, many of whom have a disability, many of whom have severe mental health issues, all of whom have trauma in their background," she said. "To cause the sorts of damage that's been caused, these kids are clearly damaged themselves."
The commissioner said she was in constant contact with the Department of Justice and provided regular briefings. She said she had met with the young people at Banksia Hill detention centre and the children held at Casuarina prison.
A 32-year-old Aboriginal man died after a suspected suicide at the prison on Sunday, which McGowan-Jones said would have an impact on the young people.
"It would have been traumatic and I think makes them more distressed because they are themselves incarcerated and so that might add to their sense of hopelessness," she said.
The WA Department of Justice refused to comment on specific cases in response to questions from the Guardian, but said young people in detention centres had "complex needs".
"Young people in custody may have complex mental health and medical needs, and the department provides appropriate care to ensure their safety and wellbeing."
The department would not provide statistics on cases of self-harm since the young people had been transferred to the facility.
