Darwin's Don Dale Juvenile Detention Centre was opened in 1991 as the first purpose built institution for young offenders in the Northern Territory.
Located in Berrimah, a predominantly industrial area of Darwin, the medium to high security centre could at that time house up to 25 boys and girls aged between 10 and 17 from all over the Northern Territory. It was later expanded to accommodate 40 detainees.
"We looked at each other in shock"
According the Northern Territory's Children's Commissioner, Colleen Gwynne, concerns about conditions at Don Dale and the treatment of five young detainees were raised on 12 August 2014 when a complaint was made by a visitor to the centre.
Four Corners has subsequently identified this visitor as solicitor, Jared Sharp, who was taken on a tour of the facility with a group of lawyers and saw five boys kept in isolation, in "inhumane" cramped and darkened cells for up to 23 hours a day.
"We all sort of looked at each other in shock that there was kids in these cells, because there was signs of life in there but we didn't know who was in there or what was happening, or how long they'd been there," Mr Sharp told Four Corners.
Less than two weeks later, on 21 August 2014, six boys aged between 14 and 16 were allegedly involved in a riot. They were reportedly subjected to tear gas in response to a disturbance sparked by an young inmate leaving his cell.
Amnesty International called for an independent investigation into the incident, and Children's Commissioner Dr Howard Bath announced he would be investigating the incidents at Don Dale.
In response to the incident and general concerns about the facility, on 23 December 2014 all detainees were moved out of the Don Dale Youth Detention Centre and into the Northern Territory's run down, old adult maximum security Berrimah Prison (which also adopted the name Don Dale Youth Detention Centre).
The 2015 Vita Review says Don Dale "struggling to maintain service"
At the same time, the Northern Territory Government commissioned a review of the territory's youth detention system, known as the Vita Review.
Overseen by Michael Vita, the former manager of Long Bay Jail in NSW and Villawood Immigration Detention Centre, the report was published in January 2015, and found that:
"Youth detention facilities in the Northern Territory are struggling to maintain service level standards in the absense of a coherent operating philosophy, staff training, direction, appropriate infrastructure, leadership and resourcing."
In February 2015, the NT Government said it was working to implement all 16 recommendations of the Vita Report and the report would be their "roadmap into the future".
Inmates ram through front gate in 2015
In June 2015, a group of six inmates reportedly caused thousands of dollars worth of damage in Don Dale's B-Block, having armed themselves with makeshift weapons.
Five of the youths forced their way on to the centre's roof, and then four of them managed to breach the internal fence.
Two of the teenagers made it over a second fence and escaped from the centre. They later smashed their way back onto the premises in a stolen car.
2015 further allegations youth detainees "caged up like animals".
Allegations of mistreatment of detainees at Don Dale centre were raised again in June 2015 by Northern Australian Aboriginal Justice Agency law and justice manager Jared Sharp, who told a public forum youth were being "caged up like animals".
"When young people are caged up like animals like that, you can understand where their psychological sense starts to deteriorate and things can become more inflamed," Mr Sharp said.
"When kids are put in [these conditions] it's a recipe for disaster."
In September 2015 a former teen inmate told the Northern Territory Youth Justice Forum that guards at Don Dale forced inmates to fight for their own entertainment, eat bird faeces for social media postings, and threatened youths were retribution on the outside.
2015 Children's Commissioner report calls out "inappropriate" and "illegal" treatment.
On 17 September 2015 the new Northern Territory Children's Commissioner Colleen Gwynne released her report.
Among the key findings were that inadequate 'de-escalation' techniques were used prior to tear gas being used on young people, that the use and type of restraints and instruments such as spit hoods were inappropriate, and the placement of young people in the Behaviour Modification Unit for long periods of time were inappropriate and at times illegal.
A few days later, a senior lawyer from the Human Rights Law Centre in Melbourne wrote to the United Nations' High Commissioner for Human Rights requesting urgent action on the treatment of young people in the Don Dale Youth Detention Centre.
Ms Gwynne told Four Corners there were still ongoing issues with youth detention in the Northern Territory, and many of her 2015 report recommendations have still not been implemented.
"The response has not been as urgent as we would have liked. The issues raised in that report are extremely serious and I would like to see a more full response," she said.
"[We need] some urgency and some dedicated resources thrown at this."