A university student died after a day out for new students went wrong and she fell 22m on to rocks in the Manawatu Gorge.

Catherine Mary Peters, 18, suffered serious head injuries during a "bridge swing" adventure activity.

The swing - popular on the adventure tourism trail - saw "fresher" students leaping from the Ballance Bridge near Woodville and swinging under the bridge on a rope tethered to the waist.

During the day out, organised by the Massey University Alpine Club, about 100 students took part in the stunt.

Police communications officer Kim Perks said about 80 people had already completed the exercise when Peters took her turn about 2.45pm.

Peters is thought to have fallen from the bridge somehow.

Perks said it was too early in the investigation to say whether people taking part were strapped in - although Youtube video of last year's freshers' day at the bridge shows students clearly attached by the rope.

"There is water down there but she fell on to stones," Perks said.

Peters was taken to Palmerston North Hospital and the area was sealed off by police.

Department of Labour health and safety staff were investigating but could not provide further details.

Members of the alpine club, which has nearly 300 mainly undergraduate members, were too upset to talk about the incident.

"I've been through a lot today," said president Jackson Wong.

Victim Support staff attended the scene and Massey University provided extra counselling support when students returned to the Palmerston North campus.

University spokeswoman Lindsey Birnie said staff would be given ongoing help.

"Anything we can do to support the students and support the student's family will be done.

"For us it won't just be today, there will be follow-up work."

A worker from the nearby Beyond the Bridge Cafe said groups of Massey students regularly took part in the bridge swing.

The rope is not believed to be in place permanently and is thought to have been installed by a private training company hired by the club.

In 2006, a female club member was injured after being struck by a boulder during a canyoning trip.

She suffered a broken collarbone and badly sprained ankle and had to be carried out by stretcher by a search and rescue team.