Another worker remains unaccounted for.
The 4m-high scaffolding was being used for a 5m by 10m section of roof slab at Bugis station. Eight workers who were working on top of the structure were injured and sent to the nearby Raffles Hospital. Four have since been discharged.
Land Transport Authority engineers are carrying out checks of similar structures at all its sites to ensure they are safe.
The S$582m (£295m) contract for Bugis station was awarded in 2008 to Soletanche Bachy – Koh Brothers Joint Venture and is due for completion in 2013.