The fence alleged was pushed over as people queued to get inside the bar. According to an eyewitness, a group of boys joined the queue shortly before 12am and began pushing other students, it was following this that the barrier reportedly fell over.
"We'd made it to the front but they refused to let any more people in until 12".
A Durham Constabulary spokesman said: "Officers are investigating the death of a student".
Owen Adams, the university's pro vice-chancellor of colleges and student experience, said support was being offered to students and staff.
"There were too many people and he couldn't get them off her".
A university student has died outside a nightclub in Britain after she was reportedly crushed under a fence. There was a metal barrier that they put at the front to stop people coming in.
Onlookers claimed a security man was seen ripping off his shirt to use as a cloth to stop the bleeding from the woman's head.
"That's when I left, as this has happened before when I've been in the queue and it's really quite painful".
He tried to give her CPR when she lost consciousness before paramedics arrived, it was alleged.
Witnesses said that there were about 600 people inside the club in the city.
Police, who were called to the scene at 11.53pm last night, have launched an investigation into circumstances leading up to her death.
An update from police is expected to be issued later today (February 8).