Ohin Construction, director and staff charged over alleged lapses linked to Tanjong Katong sinkhole

SINGAPORE: Ohin Construction, its managing director and six other individuals have been charged in court on 11 June over alleged safety, supervisory and construction lapses linked to the sinkhole that formed along Tanjong Katong Road South in July 2025.

The company faces eight charges, mainly under the Building Control Act, Workplace Safety and Health Act and Workplace Safety and Health (General Provisions) Regulations.

The charges follow investigations by the Building and Construction Authority (BCA), Ministry of Manpower (MOM) and Land Transport Authority (LTA) into the incident, which saw a car plunge into a sinkhole after part of a nearby construction shaft allegedly failed.

A female driver who fell into the sinkhole was rescued by migrant workers from the adjacent construction site and taken to hospital conscious.

Charges against company and project personnel

According to a joint statement issued by BCA, MOM and LTA, enforcement actions are being taken against seven parties, including Ohin Construction and several individuals involved in the project.

Those charged are managing director Ong Khiaw Yang Ivan, project director Raajkumar Nadarajan, project manager Sellappan Saravanakumar, qualified persons Kee Chen Siang and Yau Tze Yin, and resident engineer Senthilnathan Mathyalakan.

Ong, 64, faces six charges, the highest number among the accused.

A representative for Ohin Construction told the court that the company is under provisional liquidation.

The cases were adjourned to July.

Alleged unauthorised and non-compliant works

The sinkhole occurred beside a PUB worksite where a 16m-deep shaft was being constructed to connect existing sewer lines.

According to the authorities, the construction works involved soil strengthening using jet grout piles and the casting of reinforced concrete caisson rings.

Jet grout piles are columns of soil and cement formed through high-pressure grouting to strengthen ground conditions.

Caisson rings are reinforced concrete structures installed progressively during deep excavations to prevent soil collapse.

Investigators alleged that Ohin Construction carried out unauthorised building works, road resurfacing works and specialist building works.

The company is accused of failing to ensure that construction activities complied with approved structural plans.

Among the alleged breaches, Ohin Construction constructed jet grout piles with diameters smaller than those required and failed to conduct a mandatory jet grouting trial as well as other stipulated tests.

The company also allegedly created additional openings in a caisson ring and carried out horizontal grouting works at another ring without approval.

One caisson ring was allegedly cast in a non-circular shape instead of a uniformly circular form specified under approved plans.

Testing, monitoring and notification failures

Authorities also alleged that mandatory testing and monitoring requirements were not met.

According to the joint statement, an operational video surveillance system was not maintained at the worksite at the time of the incident.

The company is further accused of failing to notify authorities after becoming aware of a road depression along Tanjong Katong Road on 15 July 2025, 11 days before the sinkhole formed.

The charges stated that Ohin Construction did not immediately inform the Commissioner of Building Control about the road depression.

Investigators also alleged that false declarations were made regarding the appointment of a site supervisor.

The joint statement described the alleged offending conduct as including "failure to notify authorities and false declarations", alongside testing and monitoring lapses.

Workplace safety concerns

Apart from construction-related breaches, authorities alleged that the company failed to adequately protect workers' safety and health.

Ohin Construction is accused of failing to ensure that there was an adequate risk assessment and safe work procedure for horizontal grouting works.

BCA, MOM and LTA said the works proceeded without adequate risk assessment and safe work procedures.

The agencies stressed that the Building Control Act and Workplace Safety and Health Act require project parties to carry out their duties diligently and take reasonably practicable measures to safeguard workers and members of the public.

"This incident demonstrates the critical importance of proper supervision and adherence to safety protocols," the agencies said in their joint statement.

They added that enforcement action would be taken against public sector agencies, companies and individuals who fail to fulfil their statutory duties.

Incident and broader review

According to investigators, part of the shaft under construction allegedly failed at about 5.50pm on 26 July 2025, resulting in soil ingress into the excavation.

At around the same time, a sinkhole formed along Tanjong Katong Road South.

The agencies said their investigations have been completed and enforcement actions are now being pursued against parties allegedly involved in the incident.

Separately, national water agency PUB and Surbana Jurong Consultants were issued conditional warnings for offences under the Building Control Act.

Works at the project remain suspended. BCA said any resumption would require newly appointed project parties to submit fresh structural plans, which would be subject to comprehensive safety assessments and regulatory approval.

Following the incident, BCA reviewed more than 60 similar ongoing construction projects across Singapore and found no structural safety concerns, with safeguards assessed to be in place.

MOM also conducted inspections at construction sites and took enforcement action over safety lapses, including those involving excavation works, while LTA reminded contractors that road works must not commence without the necessary permits and regulatory approvals.