Cleveland Dodd, 16, was found unresponsive after harming himself inside his cell in a troubled youth wing of a high-security adult prison in the early hours of October 12, 2023.
The Indigenous teen was taken to hospital in a critical condition and later died, causing outrage and grief in the community.
Coroner Phil Urquhart said at the start of hearings in Perth on Wednesday there had never been a similar inquest in WA.
He said it was the first to be held for a young person who had died by "apparent suicide" in a youth detention centre contained in a maximum-security prison built to house adults.
Cleveland Dodd died in October 2023. (HANDOUT/SUPPLIED)
The expedited inquest has also included an unprecedented early level of involvement from the coronial investigators, including examining Cleveland's cell in Unit 18 soon after his death and supervising evidence gathering.
Despite this, Mr Urquhart said the inquest would be a limited fact-finding exercise and he could not make findings of negligence or guilt for criminal offences.
"This inquest like every other is not a royal commission: he said.
The inquest, which is expected to take 21 days, will happen in two parts, with the first set to conclude on April 12 and the second expected to start in July.
Mr Urquhart addressed Cleveland's family directly, saying he understood some would be "upset and angry that they are attending the inquest of a loved one who was so young when they died".
"There is a time and place for expressing feelings, but that time and place won't be in the courtroom," he said.
"There will be answers from witnesses you won't agree with. I understand that, but if you don't agree with any witness, you must keep thoughts to yourself."
Cleveland was found unresponsive in a cell at Casuarina Prison. (Aaron Bunch/AAP PHOTOS)
Cleveland's mother, Nadene Dodd, says her family is "still reeling from the loss of my son".
"The months since Cleveland's passing have been fraught with grief," she said in a statement read by lawyer Dana Levitt at a pre-inquest press conference on Tuesday.
"With each new detail that comes to light about the night he died or about Unit 18 generally, I become more determined to get justice for Cleveland, and for all the other boys sent there."
After the opening statements, the court will be closed so counsel and lawyers involved in the inquest and some of Cleveland's family can view Casuarina Prison CCTV footage from the night the teen self-harmed.
Witnesses who worked at Unit 18 including three youth custodial officers, a nurse and a manager are scheduled to start giving evidence on Friday, with a full day set aside for each.
Lifeline 13 11 14
Kids Helpline 1800 55 1800 (for people aged 5 to 25)
13YARN 13 92 76
Aboriginal Counselling Services 0410 539 905
7°C