A tradesman has been hospitalised after part of a 500-kilogram panel fell onto him at a Griffith worksite on Friday afternoon, Worksafe ACT confirmed.
ACT Work Safety commissioner Greg Jones said the man, aged in his 30s, was being treated at hospital, but he was incredibly lucky to have escaped with what appeared to be only minor injuries.
"We understand that the load the small mobile crane was carrying which was a screen weighing half a tonne, and that it slipped and became partially disconnected, injuring the worker," Mr Jones said.
"It appears the load was still partially supported by the crane so he didn't have the full weight of the load on him, which is very fortunate."
The incident, believed to have occurred between 1pm and 2pm, was at the Indigo Apartments - a Milin Builders site on Canberra Avenue.
CFMEU ACT boss Dean Hall had earlier said he believed the man was in a serious condition.
At about 4.30pm, Dennis Milin from Milin Builders said he was not aware of any serious incident at the site.
At around the same time, a Worksafe 'non-disturbance notice' had been placed on the site, meaning all work had stopped.
Mr Jones said Worksafe inspectors were on the site interviewing witnesses and inspecting the sited.
"We will return to work on the site tomorrow morning to continue our investigations and we will also conduct a full inspection of that site before we allow work to restart," he said.
"Any sort of accident or incident, especially involving a mobile plant carrying heavy material, has the potential for serious injuries."
Mr Jones said the incident was a reminder of the importance of safety at construction sites.
The incident came less than a fortnight after construction on the ACT courts redevelopment ground to a halt after the counterweight on a tower crane slipped at the Civic worksite.
Last August, a 62-year-old man died after a crane tipped over at the University of Canberra hospital worksite. A few months later, construction firms were urged to clean up their act when it came to using tower cranes on Canberra work sites, after five stop work prohibition notices were issued in 2016 and an audit of crane activity revealed widespread non-compliance.