WELLINGTON, April 15 - Sunday marks the 10th anniversary since six students and one teacher died in a flash flood while canyoning in the Mangatepopo Stream in Tongariro National Park. 

The students were part of a group of 40 students attending a week-long outdoor education course at the Sir Edmund Hillary Outdoor Pursuits Centre in Turangi. 

More than 60 people are expected to gather at a memorial ceremony to remember those who were lost.

Centre chief executive Graham Seatter says the memorial will be a gathering of family and friends to recognise the significance of the event. 

"The families have not been allowed to forget, obviously. For them it will always remain a very, very difficult event in their lives," Seatter told Newshub.

"It's important that we as an organisation remember it, recognise it, accept responsibility and make sure something like this never happens again." 

An investigation by the Department of Labour found the group should never have entered the gorge due to the heavy rain and the centre failed to pick up three severe weather warnings on the day of the tragedy. 

The centre admitted to the safety breaches at the time but Mr Seatter said the organisation had changed and they would not be complacent again. 

"We have a totally different safety system of the highest quality and we're a little more conservative now with our decision-making." 

"We'll just do our best to make sure young people that come here have the best time they can but have a safe time."