Warning: This story contains details that may distress some readers.

Parents sobbed, embraced and covered their faces with their hands as photos of the jumping castle at the centre of a tragedy that killed six children in 2021 were shown to a Tasmanian court.

Dozens of photos were shown in the criminal hearing of Rosemary Anne Gamble, the jumping castle operator charged with failure to comply with health and safety duties after the inflatable she provided became airborne during at end-of-year celebration at Hillcrest Primary School in the state's north.

Ms Gamble has pleaded not guilty to the charge.

Zane Mellor, Peter Dodt, Jalailah Jayne-Maree Jones, Addison Stewart, Jye Sheehan, and Chace Harrison died, and three of their classmates were seriously injured when what child witnesses described as a "mini tornado" swept through the school on December 16, 2021, tossing inflatables including the jumping castle and zorb balls through the air and across the school oval.

What became known as the Hillcrest tragedy made international headlines.

Crown prosecutor Madeleine Wilson SC gave a content warning before presenting the photos to the Devonport Magistrates Court on Wednesday morning.

She advised the images could be distressing, and allowed time for those present in the courtroom who might be affected to leave.

No-one left.

Mother heard moaning as child's name read out in court

As Ms Wilson named the children who died in the tragedy while presenting the photos, the victim's family members became clearly distressed at the rear of the court.

Two women embraced as one of the children's name was spoken, and a mother moaned loudly as Ms Wilson said her son's name.

Throughout the morning's evidence one man appeared to be staring in Ms Gamble's direction while shaking his head.

The photos were shown as agreed fact, meaning the evidence was not challenged by Ms Gamble's legal defence team.

They related to the DNA forensic evidence of blood stains found on the zorb balls and jumping castle.

The court also heard from first responder Tasmania police Constable Dean Wotherspoon on the forensic photos he took of the scene.

Photos of unused anchors shown to court 

Ms Gamble, the owner of inflatable company Taz-Zorb, has been accused of not sufficiently securing the jumping castle.

One of the photos taken by Senior Constable Wotherspoon showed a stack of star pickets with attached carabiners stamped with what he said were "safe working load" symbols.

The victims' family members appeared to be in disbelief as photos were shown of the anchors that could have been used to hold down the jumping castle.

Ms Wilson said Ms Gamble's failure related to using four pegs, which were smaller than the Australian minimum standard, when eight larger pegs could have and should have been used.

The court has been told none of those were being used to anchor the jumping castle on the day.

One of the victims' family members threw her hands up and mouthed something inaudible as photos of the star pickets were shown to the court.

Another had previously stormed out of the court after saying to Ms Gamble "yeah, thanks a lot, you did a good job" and that she should "go to jail".

Ms Gamble's defence lawyer Chris Dockray told the court during opening statements the pegs used to anchor the jumping castle down on the day were those provided by the manufacturer.

He said the appearance of the "mini tornado", commonly known as a "dust devil", was next to impossible to predict and that the weather on the day was otherwise fine.

He told the court the only way the tragedy would have been prevented was to have not held the event.

Chinese inflatable supplier appears via videolink

The company that sold Rosemary Gamble the jumping castle supplied "an average" of between four and eight pegs with its products, the court heard.

Andy Chen, the sales manager for Chinese manufacturer East Inflatables, appeared in the courtroom via video link from China on Wednesday.

Speaking through a Mandarin language interpreter, Mr Chen told the court the jumping castle was sold to Ms Gamble in November 2015.

East Inflatables provided the information in a letter dated March 24, 2022, in response to a request from WorkSafe Tasmania sent shortly after the Hillcrest tragedy.

Along with the invoice was a photo of the accessories and manuals that he said are supplied to buyers was shown to the court, which featured eight 47cm long pegs.

During opening statements Ms Gamble's lawyer Mr Dockray told the court she was only provided with four 30cm long pegs, and downloaded an instruction manual from East Inflatables' website.

However, responding to a question from prosecutor Emily Bill, Mr Chen said that "in general" and "on average … four to eight pegs" are supplied with the company's jumping castles.

He also said "in general" the company provided manuals with its inflatable products.

The hearing before Magistrate Robert Webster is expected to run for two weeks.