Police are investigating the deaths of three family members at Broken Hill in western NSW.
At about 4.30pm Thursday, emergency services were called to a home on Creedon Street, Broken Hill, following reports three people had been found unconscious in a rear shed.
On arrival, police and NSW Ambulance paramedics located a 44-year-old man, a 16-year-old boy and a 23-year-old man.
All three were taken to Broken Hill Hospital but sadly passed away.
A NSW Ambulance spokesperson said it was "a hazardous material incident".
"They've obviously been overcome by fumes," he said.
A NSW Police spokesperson told SBS News "it did not appear to involve suicide".
NSW Police officers from Barrier Police District have established a crime scene at the premises.
"It will be some time before officers can gain access safely to conduct a full investigation," a spokesman said.