VenuesWest confirmed the incident took place just after 2pm.
In a statement, a spokeswoman said at around 2pm a subcontractor carrying out painting fell through the roof, hitting the concourse floor below.
Paramedics were called and first aid was administered immediately.
“Our thoughts are with the worker and his family and workmates,” the statement says. “WorkSafe has arrived on site and is investigating. VenuesWest is fully cooperating with the investigation.”
A WorkSafe spokeswoman said it was believed the man fell between 15 to 20 metres.
WA Police is also investigating the circumstances surrounding the incident.
A spokesman said police received a report from the hospital at 3.45pm advising a man had been admitted with serious, life-threatening injuries following a suspected fall at a worksite.
He said police were currently at the scene, and inquiries were continuing.
Police will prepare a report for the coroner.