SINGAPORE: National water agency PUB and Surbana Jurong Consultants have been given conditional warnings over the 2025 Tanjong Katong sinkhole incident for offences under the Building Control Act.
The sinkhole formed after a failure at a nearby worksite, causing a car and its driver to fall into it on July 26, 2025, with workers from the worksite using a nylon rope to pull her to safety.
In a joint statement on June 11, the Building and Construction Authority (BCA), Ministry of Manpower (MOM) and the Land Transport Authority (LTA) said they have completed their respective investigations into the incident.
Aside from the conditional warnings given to PUB and Surbana Jurong Consultants, the agencies said that enforcement action is being taken against six individuals and licensed specialist builder Ohin Construction.
The alleged offences include unauthorised and non-compliant works that were carried out that did not comply with approved plans, said BCA, MOM and LTA.
“The works also proceeded without adequate risk assessment and adequate safe work procedure,” the agencies said.
They added that there were also licensing and supervisory failures and testing and monitoring lapses.
They said: “Mandatory tests that were stipulated under the approved plans were not carried out. An operational video surveillance system was not maintained at the worksite at the time of the incident.”
They added that the relevant authorities were not notified of the road depression that had occurred prior to the sinkhole formation, adding that there were also false declarations regarding the appointment of a site supervisor.
The statement did not provide specific details of the offences linked to PUB and Surbana Jurong Consultants. The Straits Times has contacted BCA for more details.
Responding to the conditional warning, PUB said it takes the matter seriously.
It noted that an internal investigation panel, convened by the Ministry of Sustainability and the Environment, had recommended that PUB strengthen its processes for identifying and responding to irregularities in projects carried out by contractors.
Among other things, the panel recommended PUB reinforce the roles and responsibilities of parties involved in its construction projects, including through regular industry engagements.
The national water agency said it has implemented the recommendations, adding: “PUB will continue to work closely with the relevant agencies and stakeholders to ensure full compliance with its statutory obligations, and that the highest safety standards are upheld across its construction projects.”
PUB said it has also terminated its contract with Ohin Construction and blacklisted it for a period of 18 months from August 2025, denying it any new PUB projects for that duration.
The incident, which happened next to a worksite along Tanjong Katong Road South, involved the construction of a shaft to connect three new sewer pipelines.
The construction works included soil strengthening works using jet grout piles and the casting of reinforced concrete caisson rings.
Jet grout piles involve the use of high-pressure water to cut the soil skeleton, followed by injecting cement grout to strengthen the soil.
A reinforced concrete caisson ring is a concrete structure that provides structural support for deep excavations. These rings are installed progressively as excavation deepens to prevent soil collapse.
The agencies said that at about 5.50pm on July 26, 2025, the sinkhole formed when part of the shaft that was under construction allegedly failed.
After the incident, BCA conducted a thorough review of more than 60 similar ongoing projects, and found no safety issues.
The agencies said that works for the project at Tanjong Katong Road South remain halted, and can only resume after the new project parties to be appointed by PUB submit new structural plans, which will then have to be assessed and approved by the BCA Commissioner of Building Control.
Ohin Construction and six individuals linked to the firm were charged in court over the sinkhole incident on June 11.
The individuals charged included the firm’s managing director Ivan Ong Khiaw Yang, 64, project director Raajkumar Nadarajan, 58, and project manager Sellappan Saravanakumar, 35.
Kee Chen Siang, 39, and Yau Tze Yin, 49, identified as Qualified Persons, and resident engineer Senthilnathan Mathyalakan, 56, were also charged.
Their alleged offending conduct included unauthorised and non-compliant works, licensing and supervisory failures, testing and monitoring lapses and the failure to notify the authorities of the road depression that had occurred prior to the sinkhole forming.
The cases will be heard again in court in July. - The Straits Times/ANN
