Police and WorkSafe inspectors on Saturday launched an investigation at an under-construction townhouse complex in Denman Prospect following the death of a worker on the site.
A 47-year-old man, who was believed to be unloading material off a truck when the incident happened, died at the scene on the corner of Ada Norris Avenue and Freebury Street.
WorkSafe ACT said in a statement the fatality happened about 11.20am. Inspectors arrived about noon. Paramedics also attended the scene. Investigations are ongoing.
WorkSafe ACT inspectors and ACT Policing's criminal investigation team were expected to remain at the site collecting evidence into the evening.
The two teams said they would work closely investigating the incident.
WorkSafe ACT was providing support for the worker's colleagues and witnesses at the scene.
"WorkSafe ACT's thoughts are with the worker's family, friends and colleagues at this difficult time," a spokesman said in a statement.
Detective Acting Superintendent Matt Craft said it was a distressing incident for witnesses.
"Our thoughts go out to the co worker and the family of the male who has deceased. It's a terrible, tragic incident. And hopefully we can prepare that information [from the investigation] as quickly as we can and get that information the coroner," he said.
Work Safety commissioner Greg Jones said a non-disturbance notice had been placed on the site in order for investigators to gather evidence.
"That non-disturbance [notice] makes sure that everything in place at the time of the incident remains there while we process that site," he said.
Mr Jones told the Sunday Canberra Times workplace fatalities and serious accidents in Canberra were isolated incidents and generally rare, even with heightened construction activity in the territory.
The man's death in Denman Prospect is the first workplace death in the ACT since Thoroughbred Park track rider Riharna Thomson, 22, died after a fall in March 2017.
A 62-year-old man died at the University of Canberra public hospital construction site in August 2016 when a mobile crane rolled over as it was being used to move a large generator at low height.
Mr Jones said the incident on Saturday should remind others in the industry to take safety on even small construction sites seriously.
"All work places, including construction sites, need to take safety very seriously. In fact, it should be their number one priority.
"And all work, no matter how simple it might seem, should be appropriately planned before being undertaken," he said.
Ada Norris Avenue was blocked to the public while investigators inspected the site on Saturday afternoon.
A report will be prepared for the coroner.