Scaffolding that collapsed at a southern Sydney construction site injuring two people was being dismantled when it buckled.
After initial inspections, WorkCover general manager John Watson said "it appears that the scaffolding was in the process of being dismantled when (Tuesday's) collapse has occurred."
"But we will know more once WorkCover's investigation is completed," he said in a statement.
Two workers who rode the five-storey rig as it collapsed at a Mascot building site on early Tuesday afternoon were injured in the accident.
One sustained cuts and bruises while the other suffered chest, leg and arm injuries.
There were no safety issues with the site, which had been inspected by WorkCover about five times during its year of operation.
About 100 people were forced from the site following the collapse.
Power lines were brought down and there were concerns fuel was leaking from vehicles trapped under the scaffolding.
O'Riordan Street was closed in both directions in response but has since reopened.
Witness Brenda Law told Network Ten she saw a man "trying to hold on as the scaffolding was falling and I could just see the terror on his face."