A young apprentice partially severed two fingers and a thumb with a power saw in one of two serious workplace incidents this week.
The ACT WorkSafe Commissioner is urging the local construction industry to put safety first in the wake of the accidents.
The first-year apprentice was using the tool on a building site in Denman Prospect on Thursday when he was injured.
He was taken to hospital for surgery on Thursday evening.
The man was the second injured recently under an MBA program after a school-based apprentice fell seven metres at a construction site in October.
WorkSafe has launched an investigation into the Master Builders' on-site supervision of the apprentice injured in Denman Prospect and there is an ongoing probe into the circumstances surrounding the fall of the 16-year-old at a Gungahlin worksite last month.
Work Safety Commissioner Greg Jones said in a statement on Thursday that he was very concerned about the injury on the site.
"This injury to a young worker is of great concern to WorkSafe and with a number of recent workplace incidents occurring in Canberra, I urge everyone in the construction industry to ensure safety remains the most important priority," Mr Jones said.
"From employers and industry representatives; to workers and unions; government and consumers; we all have a role to play in making sure that safety remains a top priority in the workplace.
"I wish to emphasise to everyone to follow their safe operating procedures carefully, make sure all workers are properly inducted into each worksite and to fully supervise apprentices and other inexperienced workers."
Master Builders ACT executive director Kirk Coningham said he was confident in the organisation's apprenticeship programs, which until recently had gone injury-free for 15 years.
"You can never be competent in the use of a tool until you've used the tool," he said.
"We know this kid is in good spirits, he's worried this will take time out of his training."
WorkSafe ACT is also involved in an incident from Wednesday, when a worker on Canberra's light rail project was lucky to survive being thrown two metres by an electric shock at a worksite.
Work was suspended at the Northbourne Avenue scene while WorkSafe ACT, ActewAGL and the building union, the CFMEU, tried to piece together what went wrong.
It is understood the man was working on locating services as part of the first phase of work on the $1 billion Capital Metro public transport project at Northbourne Avenue at Lyneham on Wednesday afternoon, when he received the shock.
He was taken hospital where he was observed for several hours before being released.
The CFMEU's ACT branch secretary Dean Hall said the incident showed again that workplace safety incident had ramifications beyond the worksite.
"Any workplace incident involving electricity is serious," Mr Hall said.
"The union hopes the underlying cause of yesterday's event can be quickly identified and the industry as a whole can learn from what happened.
"Incidents like this have wider ramifications in relation to trauma for the workers on the project, their family members and the community."
Transport and City Services minister Meegan Fitzharris said an investigation into the incident is underway and government would consider its findings.
"Safety is the number one priority for the government and community when it comes to the light rail project. We are committed to working with Canberra Metro, industry, employers, unions and employees to do everything possible to ensure every worker returns home safely," she said.
"The ACT Government takes safety on all worksites very seriously, and we have made that clear to the consortium who are delivering the light rail project."
Electricity company ActewAGL had little to say about the incident.
"The incident is the subject of a Worksafe ACT investigation and ActewAGL continues to work with Worksafe in relation to this matter," a spokeswoman said.