A plan to move 20 detained children in Western Australia to a maximum-security adult prison shows the state's justice system is broken, advocates say.
The boys, aged as young as 14, will be moved from Perth's Banksia Hill juvenile detention centre to a standalone facility at nearby Casuarina Prison.
Officials have promised they will be kept away from the adult prisoner population in safe and secure units.
They say the detainees have been destroying property, escaping from their cells, assaulting staff and harming themselves.
Advocates have been calling for urgent reform of the centre after an independent inspector found detainees were having their human rights violated.
WA's custodial services inspector in April revealed there had been multiple occasions where several boys spent less than an hour outside their cells.
A group of boys had also made repeated suicide attempts, having formed a suicide pact while isolated within Banksia's intensive support unit.
Social Reinvestment WA co-chair Glenda Kickett said the majority of children in detention had serious cognitive impairments and needed specialised trauma-informed care.
"Our youth justice system is breaching the human rights of young people, and Aboriginal and Torres Strait Islander children are the vast majority of those incarcerated," she said.
"The state government has ignored the root causes of the problems. This must be our wake-up call to fix our system and provide the early intervention, diversion, and rehabilitation supports children need in the community."
Ms Kickett urged the McGowan government to stop locking up children on remand and to raise the age of criminal responsibility from 12 to at least 14.
Greens senator Dorinda Cox said children at Banksia Hill were being traumatised in ways that would harm them for the rest of their lives.
"I am appalled that yet again, children are being blamed for what is essentially a failure of duty (of) care on (the) part of the WA government," she posted on Twitter.
WA's Department of Justice said the relocation plan would allow other detainees at Banksia Hill to return to education and other programs that had been affected by the ongoing disruptions.
About 100 of Banksia Hill's 260 cells have been seriously affected and more than 30 are unfit for use.
Corrective Services Commissioner Mike Reynolds said there had been a constant stream of contractors at Banksia Hill this year trying to keep up with the destruction of cells, with the damage bill at more than $1.8 million.
"The Casuarina site, with its new, secure units, was the only safe and suitable option to ensure the young men were able to be kept in a location away from the adult population," he said.
The cost of detaining a young person in WA is estimated about $1352 a day, a recent budget estimates hearing was told.
Most detainees at Banksia Hill were on remand and about half were expected to return to detention.
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Kids Helpline 1800 55 1800 (for people aged 5 to 25)
