Per Ununger, chief executive of the Swedish building group MVB Öst, which is the lead contractor on the site, told the Aftonbladet newspaper he was struggling to understand how the accident could have happened.
“They have an extremely high level of safety measures, so from what little I know now, it seems completely incomprehensible,” he said.
“There is a plan for the work environment and all the builders receive safety rules and safety equipment which you have to sign out when you take it.”
The accident happened shortly before midday on Saturday, with ambulances called to the scene immediately afterwards.
The building appears to have been Kvarteret Princeton, pictured in a post below.
According to local police, paramedics attempted to resuscitate the man at the scene using cardiopulmonary resuscitation, and then drove him to Karolinska Hospital where he was pronounced dead.
“The man fell from scaffolding, but the investigation will provide the rest of the details. I cannot say exactly what happened,” Christoffer Sehlstedt with the local police, told the newspaper.
According to police, the worker came from a foreign country, and as his identity was still unclear, it was taking time to contact his relatives.
Senior executives from the overseas contractor which employed the man is on the way to Sweden to support to his colleagues.
In a post on The Local's Facebook page, Damian O'Leary, who sets up safety barriers on Stockholm building projects, said it was common for builders to push them aside.
“I see it every day of the week,” he said. “When we put the roof edge safety system in place, the workers on the roof move it or take away. It's incredibly frustrating.”
Police have launched an investigation into a suspected violation or workplace safety laws which has led to a person's death.
A prosecutor from Sweden's national unit for environmental and workplace cases will be appointed to lead the investigation on Monday.