When Ashleigh Chapman heard her baby boy Heath let out a little cough she thought nothing of it and continued on eating her lunch.
A few minutes later however, she found him unconscious in the lounge room of her Mount Warrigal home, south of Sydney, where he - unbeknownst to her at the time - had earlier swallowed a balloon.
Desperate to resuscitate him, Ms Chapman immediately checked his airway, began CPR and called triple zero, with paramedics arriving within minutes and rushing him to hospital.
There, she waited anxiously as doctors worked for about an hour to save Heath's life.
"They [doctors] kept coming to ask me what happened and what led to it, but I didn't know, I wasn't much help to them. I did tell them I thought he choked on something, but they couldn't see anything," Ms Chapman told Yahoo News Australia.
"No one knew what to do. They were ruling it as SIDS (sudden infant death syndrome), even though he was awake."
He couldn't be saved and on April 8, was pronounced dead. The couple were allowed the afternoon and evening to stay with him, Ms Chapman said.
Days later she received a call with results from Heath's autopsy report and, for the first time, learned it was a balloon that had caused his death.
"They called me and said it was a really common thing, but no one knows about it," Ms Chapman said.
Through subsequent research, she was mortified to discover that 43 per cent of choking deaths were caused by balloons, according to a 1990 study based on the number of annual deaths reported to the US Consumer Product Safety Commission.
"That's a big percentage. There's nothing out there to tell me that balloons can kill like that. I knew they were a hazard, everything's a hazard when you have a baby, but not a killing hazard," she said.
The balloon that caused Heath to choke was one from an old packet they had in the lounge room, which he had shown no previous interest in at all.
One week on from the tragic accident, Ms Chapman said she felt "empty" and had been avoiding moving any of his things.
"I still believe he's going to come home - I just want that to be true," she said.
The heartbroken family wanted to share their loss in the hope of helping prevent others of enduring the same thing.
A GoFundMe fundraiser has been establish to support them with funeral costs and other expenses associated with losing a child.
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