Tasmania mourns for Hillcrest anniversary

The six children who died in a jumping castle tragedy in Tasmania have been remembered as precious and cherished, with the state's premier pledging to always walk alongside their families.

A ceremony was held on Thursday evening in the northwest city of Devonport ahead of the one-year anniversary of the fatal accident at Hillcrest Primary School.

Zane Mellor, Peter Dodt, Addison Stewart, Jye Sheehan, Jalailah Jayne-Maree Jones and Chace Harrison were killed after a wind gust lifted a jumping castle and inflatable balls into the air. 

Three other children were badly injured.

The incident happened when the students were playing on the school's oval with grade five and six classmates, enjoying end-of-year celebrations.

Their families, friends, first responders and political leaders were among those to pay their respects at the city's Market Square.

The simple phrase "forever in our hearts" was shared on a big screen.

"The 16th of December, 2021 was the most tragic day," Premier Jeremy Rockliff said.

"The loss of such cherished ... children sent shockwaves through the Devonport community, Tasmania and indeed our entire nation."

A photo montage of the six children, which also featured cards and messages of support, was played.

"We continue to keep the children, their families and their loved ones in our hearts and in our minds," Mr Rockliff said.

"Over the past 12 months Tasmanians have come together as one, wrapped their arms around everyone.

"We acknowledge though, that no matter how hard we try, no matter how hard we will continue to try, we will never be able to truly walk in the shoes of those who have lost so much.

"We will never forget your precious children and we will always walk alongside you in your grief."

Devonport mayor Alison Jarman thanked the counsellors helping the community through the recovery, adding the day was "etched in our hearts forever". 

A message from Prime Minister Anthony Albanese was also read.

"Your community is in the hearts and minds of all Australians as we remember the six beautiful children," it said.

"They were so young, yet they had already brought so much joy to this world and into the lives of those who loved them." 

People placed flowers and messages of support near a metal heart structure, inspired by the image of a broken heart shared widely on social media after the tragedy. 

Representatives from the school, which will hold a private commemoration on Friday, also attended.

Planning for a permanent memorial such as a garden or sculpture will be pursued next year.

A coronial inquest, which has yet to set a date for public hearings, will investigate the circumstances of the day.

An administrative inquest hearing was told a powerful "mini tornado" might have lifted the castle into the air.

Five of the children who died were on the castle and the other was waiting in a line.

The 174 emergency services personnel involved in the immediate response are receiving ongoing support and about a dozen are yet to return to work.

The chair of the Hillcrest Affected Area Recovery Committee, set up to help the community, has urged people to reach out if they need help.

"One year on, it has the potential to trigger reactions, emotions, depending on where you are through the cycle (of grief)," Lauchie Avery told AAP.

"The thing is to not bottle it up. If you're not feeling right, go and get some help. Whether that be family, friends or someone professional."