A roof collapsed at a construction site at Curtin University in Perth on Tuesday, killing one young worker and injuring two others.
A 23-year-old man has died and two others are injured after a glass ceiling under construction partially collapsed at Perth's Curtin University.
Police say two male construction workers were atop a building at the university at 12:30pm local time on Tuesday when the roof gave way unexpectedly.
Both men fell more than 20 metres to the ground, after which the 23-year-old was confirmed to have died.
The other man was seriously injured and taken to Royal Perth Hospital. A third man working inside the building was also taken to hospital, but his injuries are believed to be less severe.
Police and emergency crews are working to make the site safe so they can retrieve the body of the worker, whose family has been notified.
WA Police Commander Mike Bell said authorities are yet to determine what caused the roof to suddenly give way.
"A lot of the workers have stayed behind and obviously they'll be spoken to in due course to determine exactly what happened," he told reporters.
"It'll be up to the engineer to declare it safe at which point we can then go in and remove the body of the deceased and start our investigation."
Worksafe has been notified of the incident and will carry out its own investigation.
Police said the construction had been going on for months and they were unaware of any issues with the worksite.
Electrical Trades Union WA organiser Damian Clancey witnessed the incident and said it happened during the lunch break.
He said there could have been many more deaths and injuries had it happened just five minutes earlier.
CFMEU state secretary Mick Buchan said he had been made aware after the incident of there being issues with "deflection in the structural steel".
"Those issues were addressed by structural engineers...(but) I understand that there were some concerns," he said.
He said the union had not previously been aware of any concerns about the site, describing the incident as tragic.
"It's 2020. These events should not occur in the building and construction industry," he said.
"We're seeing all around Australia, incidents similar to this ... poor procurement, cheap tendering, poor design or under-design on construction projects."
With additional reporting by AAP.