Seven workers were injured at a construction site along Braddell Road on Wednesday morning in the second worksite accident this week.
Safety officer Lenin Venugopal, 35, said one worker was seriously hurt but conscious after the suspended scaffolding on the second level of the building collapsed.
A worker is believed to have been clipping his harness to the scaffolding when the structure became unbalanced leading to its collapse, said Mr Lenin. Another six workers were injured but they were conscious and seated when The Straits Times arrived at the scene.
A 23-year-old worker from China, who wanted to be known as Mr Liu, said he was on the second level scaffolding when it collapsed, but he was unsure of what happened. He injured his legs. A spokesman for the Singapore Civil Defence Force said it received a call for assistance at 11.40am. The site will house a new building in an industrial cluster.