Work at all public road and rail worksites was suspended for half a day yesterday after part of a new viaduct that was being built collapsed early in the morning, killing one worker and injuring 10.
The Land Transport Authority (LTA) used this "timeout" to review safety measures at all its rail and road projects all morning, before work resumed at 1pm.
Work remains suspended, however, at the $94.6 million project to build the viaduct in Upper Changi Road East, where a portion of the structure collapsed in the early hours of yesterday morning. The Building and Construction Authority revoked the permit for works at the project as the authorities conducted their investigations.
The project had been awarded to Or Kim Peow (OKP) Contractors, which was expected to complete it by the first quarter of 2020.
Shares of the mainboard-listed OKP crashed 8 per cent in the wake of the accident, before trading was halted at 10.15am.
OKP has been pulled up for safety lapses previously, and was blacklisted between January and April this year.
The latest accident took place at around 3.30am, when a portion of the structure collapsed. Eleven workers who had been working on it fell from a height of around 4m.
Preliminary investigations by the LTA showed that corbels - structures put in place to support the weight of precast beams between two sections - had collapsed.
A 31-year-old Chinese national was pronounced dead at the scene, while 10 others were taken to Changi General Hospital. Seven remained warded, with two in intensive care, while three were discharged after treatment.
OKP, which has been in construction since the 1960s, said in a statement to the Singapore Exchange that it was "deeply saddened" by the accident. It said it would "assist and cooperate fully with the authorities in their investigations".
Just three days earlier, OKP was fined $250,000 in connection with another incident on Sept 22, 2015. Four workers fell 6.4m after a section of the working platform they were standing on - under a flyover being constructed in Yio Chu Kang - became dislodged.
Between January and April this year, OKP was put on a Ministry of Manpower blacklist after receiving 25 demerit points for lapses.
Yesterday's incident brought the number of reported worksite fatalities to 20 this year. There were 66 fatalities last year.
Second Minister for Transport Ng Chee Meng said yesterday's incident was very unfortunate, and he was "saddened" by it.
Speaking on the sidelines of the opening ceremony of the ninth Asean Schools Games yesterday, Mr Ng, who is also Minister for Education (Schools), said: "I have told LTA to extend the best assistance we can to the workers who are injured.
"Investigations are ongoing, the LTA is looking into what has happened together with the Ministry of Manpower, and we will get to the root of the causes so that we can learn the lessons to prevent another such incident from happening."
Meanwhile, the LTA is building a temporary road alongside the slip road below the viaduct which had been made impassable by debris after the collapse.
This is so that SBS Transit's bus service 24, which had been diverted because of the incident, can revert to its original route.
LTA added that it will carry out a thorough safety and design review of the temporary road before opening it for public use by noon today.