Hillcrest Primary School students Zane Mellor, Peter Dodt, Jalailah Jayne-Maree Jones, Addison Stewart, Jye Sheehan and Chace Harrison died after the incident in December 2021.
They were enjoying end-of-year celebrations on the oval of the school in northwest Tasmania when a wind gust lifted the castle and several inflatable balls into the air.
Two other children were badly injured in the accident which made worldwide headlines.
Rosemary Gamble, the owner of Taz-Zorb, which set up the equipment, faces a hearing due to begin on Tuesday in Devonport Magistrates Court.
She has pleaded not guilty to workplace health and safety law breaches.
Gamble, who was charged in November 2023, is accused of failing to ensure the anchorage system was sufficient to prevent the castle from lifting.
It is alleged the castle was tethered at four of its eight anchorage points, not in line with the manufacturer’s instructions which required a peg at each point.
Gamble arrived at the school with two workers, and set up the castle and zorb balls.
She is accused of failing to provide the workers with information including the manufacturer’s operating manual for the castle.
According to court documents, seven students were on the castle when a “significant” weather event caused it to become dislodged.
They fell from the castle, while a blower attached to the castle to keep it inflated struck a nearby student.
Engineering and weather experts and the castle’s Chinese manufacturers are expected to be among witnesses across the two-week hearing.
Defence and prosecution lawyers have agreed to some facts in the case, meaning eye witnesses, including children, won’t have to give evidence in court.
Gamble’s lawyer has previously raised concerns about her safety and asked the court about what security provisions will be in place.
The court was told the castle and other inflatable equipment would be set up on Monday at an undisclosed location and viewed by the presiding magistrate.
The hearing is being streamed to a nearby function centre because of the level of public interest and the small size of the court room.
