Like 2.7 million Australians, Nathan Reynolds had asthma - and his family wants to know why he wasn't provided with basic medical care before his death in a Sydney jail in 2018.
The inquest into Mr Reynolds' death began on Monday more than two years after the 36-year-old took his last breath on the floor of Outer Metropolitan Multi-Purpose Correctional Centre about midnight on September 1, 2018.
"Nathan died on the cold floor of a prison, with no loved ones around him. He was just 36 years old - he died far too young," his younger sisters Taleah and Makayla Reynolds said in a statement on Monday.
"We're here today because we want to know the truth and we want justice for our brother - we want to make sure that no other family should have to go through this pain."
NSW coroner Elizabeth Ryan will be asked to consider what level of medical treatment Mr Reynolds received in the months before his death as well as whether prison staff acted appropriately on the day of his death.
She began by acknowledging the coroners court was on Indigenous land and expressing her sincere sympathy to Mr Reynolds' partner, sisters and mother seated in court.
"We know you loved him very much and for this reason, inquests can be painful and sorrowful," Ms Ryan said.
Counsel assisting the coroner Chris McGorey said there was no dispute Mr Reynolds died of bronchial asthma after radioing correctional officers at the South Windsor jail that he was having trouble breathing.
After that 11.27pm call, it took guards 13 minutes to arrive to Mr Reynolds' wing of the prison.
The sole registered nurse at the prison complex arrived another nine minutes after, at 11.49pm.
CPR began sometime before paramedics arrived about 12.14am. Mr Reynolds was pronounced dead at 12.44am.
A medical expert is expected to tell the inquest that the Rooty Hill man's respiratory condition was already severe and life-threatening when he called for help, Mr McGorey said.
"The window of time to intervene and prevent his death was very narrow," he said.
Issues for the inquest included whether the severity of Mr Reynolds' asthma was recognised and appropriately identified by prison staff when he entered custody in May 2018.
During a stint in a Bathurst jail, Mr Reynolds was hospitalised for asthma in which his peak expiratory flow indicated his lung function dropped to 10 per cent capacity, the inquest was told.
"That objectively demonstrates how severe Nathan's asthma was," Mr McGorey said.
Karly Warner, the chief executive of the Aboriginal Legal Service NSW/ACT, which is representing the Reynolds family at the inquest, said more than 440 Indigenous people have died in custody since the Royal Commission into Aboriginal Deaths in Custody in 1991.
That equated to an average of one death every three weeks, she said.
"We're standing in solidarity with the Reynolds' family today and their calls for justice - there must be accountability for Nathan's death, and swift action to put an end to tragic and preventable deaths," she said in a statement.
