A wind event on the day a jumping castle was lifted into the air resulting in the deaths of six children at a Tasmanian primary school has been described as a "mini tornado".
During a coronial update provided to the families of the children killed or injured at Hillcrest Primary School in December last year, counsel assisting Leigh Mackey told the court the event could be described as "a mini tornado, a wind devil, or similar".
"It appears to have been powerful and concentrated," Ms Mackey said.
Coroner Olivia McTaggart is leading the investigation into what happened, describing the event as "catastrophic".
On Tuesday, she provided details on what evidence has been collected, including details of the injuries suffered, and the next steps toward a public inquest.
"I recognise that this event and the deaths of the children has greatly affected so many people," Coroner McTaggart said.
"It's an event that has touched and saddened the whole Devonport community, and it's had such an impact on Tasmanian citizens as a whole."
The investigation process was described as "intensive" and "complex".
Peter Dodt, Jalailah Jayne-Marie Jones, Addison Stewart, Jye Sheehan, Zane Mellor, and Chace Harrison died in the tragedy.
Counsel assisting the coroner Leigh Mackey said two of the students died at the scene, while the others died at hospitals around the state.
She told the court it is believed five of the students who died were on the jumping castle, while the sixth was waiting in line for an activity and was struck by an object.
"The jumping castle and zorb balls were inflated, secured, operated and supervised by three TasZorb personnel on site," she said.
"Small groups of children were permitted on to the castle at a time for short periods."
Three students playing in inflatable zorb balls were injured but survived, while two other students playing on the jumping castle also survived.
The court was told a total of 39 students had been on the oval for 45 minutes before a wind event happened at the school.
A joint public inquest will be held into the deaths, but the court heard it won't be held for at least another six months due to the complexity of the matter and the extensive level of evidence to work through.
Evidence collated so far includes video records of interviews with students from the primary school, affidavits from witnesses, emergency responders and the forensic team, in addition to triple zero transcripts, body cam footage and data from the Bureau of Meteorology and expert reports for preliminary weather expert opinion.
Evidence from a WorkSafe Tasmania investigation and a report from a weather expert engaged by the coroner are yet to be received.
