There is a kind of grief that claws at your insides, constantly, without subsiding.

Key points: Jozef Maragol and Anet Eyvazians dropped their daughter Arianna off at childcare in August 2018

Jozef Maragol and Anet Eyvazians dropped their daughter Arianna off at childcare in August 2018 In the morning, Arianna died during a sleep

In the morning, Arianna died during a sleep Her parents are still waiting to hear what exactly happened to their daughter

It is the kind that often springs from an unexplained death or absence, a sudden shocking loss for which no reason is given. It is a grief that can consume you.

And it is this grief Jozef Maragol and his wife Anet Eyvazians say has shattered them.

"Our lives have been destroyed", Ms Eyvazians told 7.30.

"Every day we wear a mask."

When Mr Maragol talks of his daughter, Arianna, his eyes often swing skywards. He describes the child he lost when she was just 16 months old as an angel.

"She's always with us and she never left this house," he said from the pristine home they built in Sydney's western suburbs.

"We miss her every moment."

They both wear sparkling butterfly brooches on their chests to represent Arianna: "We carry her always with us in our heart," Ms Eyvazians said, struggling to speak through tears.

'I'll see you in the afternoon'

The family were looking forward to a holiday when Arianna died. ( Supplied: Anet Eyvazians )

Their grief has been particularly acute because, more than a year later, they still do not know what caused their daughter's death.

All they are sure of is that they dropped off a smiling little girl at her childcare centre on the morning of August 24, 2018, and that when they next saw her — that afternoon — she was dead.

Ms Eyvazians said Arianna woke early, with a slight temperature, which dropped back to normal after she gave her some Panadol and she brought her to bed for a cuddle.

But the family was excited, they were on the cusp of a three-week holiday with Ms Eyvazians's brother.

On the way to Berry Patch childcare centre, Arianna was dancing and clapping in the car and her father clapped and sang along with her, teasing her. It was, he says, "a normal day".

He told the staff she might be a little tired, before handing her over.

"I just kissed her hand and I told her 'Baby, I'll see you in the afternoon'," Mr Maragol said.

What happened after that is not entirely clear.

'She's not responding'

Arianna was taken to the Children's Hospital at Westmead. ( ABC News: Lily Mayers )

Arianna was put down to sleep a little after 9:00am.

Meanwhile, at her workplace, Ms Eyvazians was checking in on the Berry Patch app that allows parents to see their children's schedules of eating, sleeping and playing.

She saw that Arianna went to sleep just after 9:00am. When there had been no update by 10:50am, she called the centre to ask after her daughter and was told she was fine.

Shortly after noon, Mr Maragol received a call from Berry Patch, in which he was told his child was "not responding" and that paramedics were working on her.

Head spinning, he rushed to pick up his wife and then went to Westmead Children's Hospital.

The couple was shown to a room where a doctor and a social worker told them their daughter was dead.

"We couldn't believe that we were going to see our lifeless child on a bed," Ms Eyvazians said.

"How could this happen? I just called not long ago to check on her and they said to me 'She's fine'.

"But then we got the call that she's not responding. And then the doctor said that she's passed away.

"I couldn't even believe that. And it didn't make sense for us. And we couldn't believe that. It's Arianna."

Mr Maragol was in shock.

"I was trying to understand: Is this us? Is this happening to us? What we are going through?" he said.

"Everything was taken away from us. Every single dream that we had forever for her."

A search for information

No-one from the Berry Patch childcare centre has contacted the Maragols. ( ABC News )

No-one from Berry Patch was at the hospital to meet them, or talk to them about what happened. Nor has anyone from Berry Patch called, emailed or contacted them since.

It is this, they say, that stings them most.

When they logged on to the Berry Patch app to double-check their daughter's schedule, the Maragols discovered they had been logged out.

"Even on that day when we were in the hospital with a lifeless child, I wanted to see what happened in the app to see any updates, like who checked on her. But unfortunately, they locked us out from the app," Ms Eyvazians said.

"And that was a main question. Why? Why they did that. Why?"

The Maragols' request to talk to other parents with children at the centre was also denied.

At 8:32pm on the day Arianna died, Berry Patch put out a statement attributing her death to a "medical episode".

This baffled her parents.

Mr Maragol said the autopsy was inconclusive and the cause of death was "unascertained".

He said Arianna had been in hospital earlier that year after she reacted to vaccinations and developed a fever of 39.8 degrees Celsius.

She was tested for a couple of days before doctors concluded she was suffering from three viruses simultaneously.

Ten days before her death, she had a mild cold. Apart from that, her parents insist she was a perfectly healthy child.

Best practice sleeping checks

Red Nose chief midwife Jane Wiggill says that all sleep checks should be physical. ( ABC News: Laura Kewley )

A year before Arianna passed away the federal childcare authority ACECQA revised its national standards following an inquest into the death of a five-month-old — Indianna Hicks — who died suddenly and unexpectedly in care on the Sunshine Coast, in 2012.

These mandated that staff "are always within sight and hearing distance of sleeping and resting children so that they can assess a child's breathing and the colour of their skin".

The Berry Patch policy states that every child is to be checked on every 10 minutes.

When the family received a log of the checks undertaken on Arianna on August 24 — through a Berry Patch lawyer — they discovered the times of checks were irregular, with one 20-minute slab, then a 30-minute break, then 23 minutes, then 24. The last check was at 12:02pm.

The policy, and the log, does not specify how checks are made.

Notes from an assessment of the Berry Patch by an Education Department officer. ( ABC News )

In the last assessment of the Berry Patch Centre undertaken before Arianna's death, in 2014, the officer from the Education Department raised a concern with the staff: while cot checks were meant to occur every 10 minutes, she observed, educators "don't actually walk into the cot room, just check screen — how can you tell [children] still breathing?"

The staff member told her, "we see them moving around", then staff members can go into the cot room, "to check".

Sleep policies are supposed to be based on the current best practice, usually determined by Red Nose, a charity established to eradicate SIDS.

Jane Wiggill, the chief midwife at Red Nose, is in charge of setting the best practice sleep guidelines.

Regular intervals are important, she says, but it is the quality of the checks that is crucial.

"Staff need to be going in there and looking at these babies and looking at these children, looking at the skin, looking at the breathing," Ms Wiggill said.

"They need to be close enough to hear and see these children. In my opinion, it's not sufficient to check a baby through a monitor or a viewing window or a doorway."

Ms Wiggill believes the national standards are open to interpretation, and Red Nose has called for them to be changed so that all sleep checks are physical.

'What has happened?'

Jozef Maragol and Anet Eyvazians want to make sure no-one has to go through what they have. ( ABC News )

The Maragol family has many unanswered questions.

Why was Arianna left to sleep on her stomach, which is how the detective told them she was found? Why was she left to sleep for almost three hours, well beyond what they claim is her usual morning nap? Why wasn't she woken for her lunch? Why did someone not wake Arianna when her mother called at 10:50? And what kind of checks were carried out?

"When I call them, I was expecting that they checked on her physically," Ms Eyvazians said.

"But I don't know if they did that or not."

Their anxiety is not just about Arianna, but the care of other children.

"The constant question that comes to mind is: 'What has happened?'," Mr Maragol said.

"This is just one day that we have noticed, what has been happening other days, not only to our kids but other kids?

"How could we make sure our kids are looked after by these centres?"

Their concerns are that there may be a systemic problem, a lack of robustness in, or accountability for, sleep policies across thousands of early childcare centres in Australia.

Mr Maragol advises parents to ask hard questions.

"[Parents should ask]: How do you look after my kids? How do you check on the kids? How do you perform your checks?" he said.

"What system do you have to check the kids? Is there a monitoring system or CCTV camera for noise? For movement?

"How does someone … enforce those policies?

"If the system is broken, let's fix the system. If the system needs help, let's help that system. But by not trying to solve the problem, the problem won't go away."

The Maragol family eventually hired a lawyer to help them obtain information.

A few months ago, the lawyer put in an FOI request to the Education Department to try to obtain a copy of any internal inquiries into Arianna's death.

A request to waive the fees for this request was denied, and no formal answer has been supplied.

More than $20,000 in legal fees later, they remain in the dark.

"No-one likes to talk to us," Mr Maragol said.

"Everyone has moved on, whereas we [are] stuck in that pain forever."

Centre rating increased

The Australian Children's Education & Care Quality Authority (ACECQA) rating system. ( Source: ACECQA )

On August 12 this year — just shy of a year from Arianna's death — the Berry Patch childcare centre had their ACECQA rating increased from "meeting" expectations to "exceeding" expectations.

A spokeswoman for the Department of Education said that even though a coronial inquest might still be pending, parents still expected regular inspections to be undertaken of all childcare centres and that Berry Patch had met all the requirements of the National Quality Standard, improving in some areas.

"Once the Department of Education receives the brief of evidence from police, it will undertake its own investigation into what occurred on the day and whether there were any breaches of the Education and Care Services National Law and Regulations," the spokeswoman told 7.30.

NSW Education Minister Sarah Mitchell did not provide answers to the questions 7.30 sent to her regarding the incident, the assessment, and the nature of sleep policy.

The Opposition spokesperson for education, Jodie Harrison, said the fact that "a serious incident" that had been referred to the Early Child Care Education Directorate had not been considered in 2019 was a concern.

"Minister Mitchell should have been taking a very active interest in the assessment of this service," she said.

"But disturbingly it seems that hasn't been the case at all."

The Berry Patch childcare centre also declined to answer a list of questions from 7.30 about what happened on the day of Arianna's death, why there were such long gaps between checks on her and, crucially, whether anyone physically examined Arianna during the near three hours she was in the cot.

In the NSW Education Department officer's notes for the 2019 assessment of Berry Patch, which the NSW Opposition obtained through a Standing Orders request, she observes that after a buzzer sounds, "an educator walks into the cot room to check the infants who are sleeping, places her hand on their back and checks their positioning".

The matter is now before the coroner and the family hopes that it will result in an inquest.

A voice for other parents

Jozef and Anet keep a memorial to Arianna in their home. ( ABC News )

Meanwhile, every day, the Maragols stare at the inchoate puzzle of their daughter's death as they wait to hear if the coroner has made a decision.

In the corner of their living room is a small shrine to Arianna, featuring portraits of a pretty, happy child lit by flickering candles.

Tiny angels dot tabletops and shelves — clay, ceramic, straw — as their six-month-old son Samuel plays quietly.

His birth gave them hope and purpose, they said, a reason to wake up.

Their friends tell them how much he resembles his sister.

Their Christian faith, too, has kept them alive.

"If we didn't have our Lord holding on our hand we wouldn't be here today," Mr Maragol said.

When one of them is down, the other is up.

"And I think this is only by the blessing and the love that God has given us once again. He's shown us that he hasn't forgotten", he said.

But the grief, and stress of not having answers about Arianna's death, eats into their days.

Mr Maragol, an IT specialist, often has to take breaks at work to compose himself.

"I have to just clear my head because I miss her so much. Because she made me to be a dad for the first time," he said.

"That love that I never experienced in my life — not being able to see that love. How could I move forward?"

Ms Eyvazians said it has been difficult waking up every day realising that Arianna is no longer with them.

"And it's hard that we are not going to see her growing up. We're not going to see her playing with her brother. We're not going to see how she would have looked. We are missing all of this," she said.

"Our life is shattered in a million pieces. That's how we feel because it looks like no-one cares about Arianna, no-one wants to provide information to us, answer our questions.

"And as parents, we want to know what happened to our daughter. We want to know what went wrong."

After much thought, they decided to tell their story in the hope of preventing other tragedies.

"We want to be a voice for other parents," Mr Maragol said.

"We want to make sure that no other parents go through the grieving, the pain, the suffering that we are going through."