Families of six children killed in a primary school jumping castle accident are angry and in disbelief after a court dismissed a workplace safety charge against its operator.

Chace Harrison, Jalailah Jayne-Maree Jones, Zane Mellor, Addison Stewart, Jye Sheehan and Peter Dodt died after the incident at Hillcrest Primary School in Tasmania in December 2021.

They were enjoying end-of-year celebrations on the school’s oval when a wind gust lifted the castle into the air.

Three other children were seriously injured in the accident.

Rosemary Gamble, owner of Taz-Zorb,which set up the equipment, had pleaded not guilty to failing to comply with a workplace health and safety duty.

She was accused of failing to anchor the castle properly.

In delivering his decision in Devonport Magistrates Court on Friday, Magistrate Robert Webster said Ms Gamble “in some respects” failed to comply with her health and safety duties.

“However, I am not satisfied, pursuant to [the charge] those failures were a substantial or significant cause of the children being exposed to the risk of serious injury or death,” he said.

Webster said the incident occurred due to an unprecedented weather system, namely a dust devil which was “impossible to predict”.

“Ms Gamble could have done more or taken further steps,” he said in his written decision.

“However, given the effects of the unforeseen and unforeseeable dust devil, had she done so, that would sadly have made no difference to the ultimate outcome.”

Webster told the court the charge was dismissed and Gamble was “free to go”.

Georgie Burt, mother of Zane Mellor, yelled at Gamble inside the courtroom after the decision was handed down.

“I hope you see them every time I miss a birthday, miss a Christmas,” she said.

A representative of Gamble read a statement on her behalf outside court, saying she recognised the scars of the incident would likely remain forever.

“I never meant for something like this to happen. And I am just so sorry that it did,” the statement said.

“I am a mother. I can only imagine the pain that other parents are living with each and every day because of this terrible thing that happened.

“Their loss is something I will carry with me for the rest of my life.”

Andrew Dodt, the father of Peter Dodt, said he had been broken for a long time.

“Our hopes are just shattered now,” he said.

“At the end of the day all I wanted was an apology for my son not coming home and I’m never going to get it and that kills me.”

Gamble faced a 10-day hearing in November where it was alleged she only used pegs at four of the castle’s eight anchor points. The manufacturer’s instructions recommended all eight be used.

Lawyer Chris Dockray argued Gamble had been left out to dry by the castle’s Chinese manufacturer.

East Inflatables provided no instructions to Gamble upon purchase and supplied only four pegs, Dockray said.

She downloaded a two-page manual from the company’s website, he said, leading to an interpretation that four pegs were sufficient.

Preparations for an inquest were paused due to the criminal proceedings, while a class action has been launched against  Gamble and the state of Tasmania.

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-AAP