A new report has heavily criticised the way in which the Ministry of Education handled the post-earthquake Christchurch school reshuffle in 2012.
The announcement in September 2012 that 13 schools would be closed and 18 merged was met with widespread shock and confusion at the time.
The Canterbury Primary Principals' Association said its inquiry found the reshuffle was rushed, and created long-lasting trauma and anxiety for schools and children.
It said schools and communities were unprepared for the major overhaul, which should have been made with less haste and more consideration for the stress locals were enduring.
Association president Jeanette Shearer said the results of its research were telling.
"The inquiry actually found that it could have been handled better and that it had created trauma for people, yes.
"There was confusion over how the choices had been made, and I think the feeling of the sector was there was no consultation prior to that."
The effects were ongoing today, she said.
"I think the people who were directly affected, whose schools were closed, who may have lost jobs, definitely it would still rankle with them the way it was done and the devastation that it caused for them."
At the meeting announcing the closures and mergers, principals were given colour-coded name tags, which ultimately revealed their school's fate.
Toni Burnside, who was the principal of now-closed Central New Brighton School, said it felt like the rug was being pulled out from underneath.
"It was only just the year after the earthquakes and we could see in our families and our children that we were the stability," she said.
"There was so much going on in [their lives], and school was the place where they could come to - the people were the same, the routines were the same - we were the safe haven."
"When it was proposed that we merge, to shake that up at that moment in time was absolutely the wrong thing to do," she said.
Minister should apologise, Labour says
Acting Secretary for Education Katrina Casey acknowledged the process was unsettling for schools and communities.
"We accept that the beginning of the process wasn't as good as it should have been and that had an impact. But what we also know is that the decisions that were made, several years later when we see the kids in their new environment, were the right thing to do."
She said the changes - some of which were still ongoing - covered 85,000 students in more than 300 early childhood centres and 200 schools.
"At every point after that we significantly improved the process and went further in supporting the process than we had ever done before - we listened and improved the process as we went."
Ms Casey said the scale of the devastation was something the ministry had never encountered.
Labour Party education spokesperson Chris Hipkins said it was now up to Education Minister Hekia Parata to apologise to the Christchurch community for the hurt.
"The apology's long overdue," he said. "It was a really horrific process from start to finish. There was enormous goodwill in Christchurch towards the government around making changes as a result of the earthquake.
"Hekia Parata managed to burn off all of that goodwill by handling the process so badly."
The minister's office declined an interview.
It said Ms Parata had previously acknowledged it was a really bad process, and all school engagement since then has been much better.