Grace Fu apologises over Tanjong Katong sinkhole; ministry to convene internal panel

SINGAPORE: The Ministry of Sustainability and the Environment (MSE) will convene an internal panel to investigate the cause of the sinkhole that appeared along Tanjong Katong Road on Saturday (Jul 26).

Speaking at the sinkhole site on Tuesday (Jul 29), Minister for Sustainability and the Environment Grace Fu apologised for what she called a “serious incident” that “should not have happened”.

The sinkhole appeared along Tanjong Katong Road South on Saturday, causing a car to fall in. It was adjacent to a PUB worksite that involved the construction of a 16m-deep shaft.

The driver of the car was rescued by migrant workers working nearby and taken to Raffles Hospital.

“On behalf of MSE and PUB, I would like to extend my apology, my sincere apology, to the injured driver for her injury suffered, as well as going through a harrowing experience," said Ms Fu.

She also apologised to members of the public and residents in the area "for causing anxiety and unease", and motorists and commuters for the inconvenience due to the road closure. 

The internal panel will be made up of “very experienced people in this area with various expertise”, she said, and national water agency PUB will fully cooperate with the Building and Construction Authority (BCA). 

BCA said on Monday that it will start an independent investigation into the incident. The investigation will examine the circumstances leading to the formation of the sinkhole and identify the root causes. The agency said investigations could take several months. 

“I think in this case, having two teams looking at it is helping us to find out more thoroughly and systematically what are the causes of this sinkhole,” she said, adding that the investigations will be of “similar time frame” to BCA’s. 

Asked if the emergence of the sinkhole could be linked to a burst water pipe that occurred the night before, Ms Fu said the public can be assured that they will look at all evidence made available to them. “We will study and report on the findings,” she added. 

Responding to residents’ complaints of noise from repair works through the night, Ms Fu said that it was a “fine trade off”.

“The more we stop work at night, we may not be able to conduct the rectification work as quickly as we like,” she said. “We’ll do our very best to mitigate (the noise) to its fullest, but I hope that the residents will also understand that we want to do this quickly to stabilise the situation so that public safety is protected.” 

On Monday night, PUB said it was testing the stability of the ground. 

The shaft was backfilled to stabilise the surrounding ground, and the sinkhole was filled with liquefied stabilised soil, the national water agency said. 

PUB added that it was conducting "rigorous tests and scans to detect underground cavities and verify ground stability" before continuing with repair works. 

The agency is also conducting thorough safety assessments in consultation with BCA and the Land Transport Authority before the road is reopened to the public.

A concrete component in the shaft, known as a cassion ring, had failed at around 5.50pm on Saturday, PUB said. It is not clear what contributed to the failure of the component. 

PUB has since called for a safety time-out to review sewer works similar to the incident site.

Tanjong Katong Road South between Mountbatten Road and East Coast Parkway will be closed until further notice for repairs.