A young man has died in hospital after a brick pillar collapsed onto a hammock he was laying on in Subiaco early this morning.

Jake East, 22, and his girlfriend Carley Kempton were in the hammock in the backyard of a unit when a pillar it was tied to gave way about 12.30am.

It is understood Mr East, a physiotherapy student at Notre Dame University, bore the brunt of the impact and was critically injured.

Ambulances were called and both were taken to Royal Perth Hospital.

Camera Icon Police arrive at the unit this morning following the collapse of the pillar just after midnight.

Mr East was being treated in the intensive care unit but died this morning.

Ms Kempton, 22, is not believed to be badly hurt and her condition is listed as stable.

The pair were among friends at the unit having a house party.

A neighbour said he heard a loud bang about 12.30am, which he initially feared was an intruder.

He went outside and noticed the music from the unit had just been turned off but he did not hear any screams or commotion.

Camera Icon The hammock was attached to a brick pillar in the backyard of the Subiaco unit.

He said he had not realised until today that anything was seriously wrong and described it as a tragedy.

Another neighbour saw two ambulances and a fire truck in the street but did not know what happened.

The pillar that broke apart was one of several holding up a pergola at the ground floor unit.

Police will investigate for the Coroner.