Burwood School deputy principal Sandra Jamieson was supervising swimming lessons for 100 pupils at the QE II pool complex when the February 2011 earthquake struck.
She recalls a "tidal wave" sweeping some of the children out of the pool.
"It was quite amazing. It was such a jolt and a huge wave washed up and back down the pool," Mrs Jamieson said.
"We had 50 children in the pool and another 50 waiting in the grandstand. Some were actually swept out of the pool.
"It was the shock of it for a start - then the realisation we had 100 children that we had to get back to school safely."
Mrs Jamieson and colleagues Tanya Keeling, Mandy Hadfield and a relieving teacher had to cope with an immediate evacuation.
"We had to leave the building and we had to leave all the children's clothes behind," she said.
With power gone, some of the children had to be escorted along a long dark alleyway away from the training pool, which Mrs Jamieson said was "reasonably scary".
"It was a very quick evacuation. I remember looking back to make sure everyone was out. We had wet and cold children but we were lucky it was a warm day."
Mrs Jamieson said pool staff were "fantastic" and found emergency blankets for the children.
Stranded, with no chance of the bus returning to pick them up, the teachers had to organise transport.
Mrs Jamieson said they texted the school and quickly arranged for about four or five cars to ferry the children back to school.
"It was a long day. We were there about four hours," she said.
"Some parents arriving to pick their children up at school - some on foot - had been distressed to learn the kids were still at the pool."
Mrs Jamieson said during the emergency she had little time to think too much about the safety of her own family members.
"Probably the adrenaline kicks in. You don't worry about yourself or your family. You just realise you've got all these children to look after and you've got to get them back safely," she said.
"That's all you think about. It's an automatic reaction."
Mrs Jamieson said the experience had left her wary of trips with children outside school.
"You definitely think more about what you have to do safety-wise and if (the trip) is worth the risk."
The school had upgraded its safety plans since the earthquakes and teachers on trips away from school took lists of names and parent contact numbers with them.
- By Cullen Smith of The Star
