Tanjong Katong Sink Hole (2025)

The Tanjong Katong Sinkhole incident that occurred on July 26, 2025, was a significant event involving a road collapse that captured public attention and raised concerns about urban infrastructure safety.

Photo from The Straits Times.

Incident overview

The sinkhole appeared at approximately 5:50 PM on July 26, 2025, along Tanjong Katong Road South, near its junction with Mountbatten Road. A section of the road collapsed, creating a sinkhole approximately 2-3 meters deep and spanning two lanes. A car driving along the road fell into the hole, though the driver, a woman, managed to exit the vehicle and was rescued by nearby construction workers within minutes. The sinkhole filled with water due to damage to underground water pipes caused by the ground movement. Water supply to about 18 households was temporarily disrupted but was fully restored by 2:30 AM the following day.

Rescue and response

Worker that saved the lady that was in the car. Photo from Reddit.

Construction workers from the adjacent PUB worksite (Ohin Construction) quickly assisted the driver by throwing a rope to pull her to safety. The Singapore Civil Defence Force (SCDF) arrived later and commended the workers for their bravery. Multiple agencies, including PUB (Singapore's national water agency), the Land Transport Authority (LTA), and the Building and Construction Authority (BCA), coordinated efforts to stabilize the area, conduct safety checks, and initiate repairs.

Tanjong Katong Road South was closed indefinitely between Mountbatten Road and East Coast Parkway (ECP) for repairs and safety assessments. Bus services 36 and 48 were diverted during this period.

Cause of the sinkhole

Car that fell into the sinkhole. Photo from MustShareNews.

The sinkhole occurred adjacent to an active PUB worksite involving the construction of a 16-meter-deep shaft to connect sewer lines. A concrete component in the shaft, known as a caisson ring, failed around the same time the sinkhole formed. Experts suggested that the sinkhole likely resulted from gradual soil erosion caused by underground leaks or excavation works, rather than a sudden event. A burst water pipe reported in the area the night before may have contributed to soil washing away, creating underground voids. BCA initiated an independent investigation to determine the exact cause, which was expected to take several months due to the complexity of the incident.

Safety measures and repairs

The sinkhole and adjacent shaft were backfilled with liquefied stabilized soil (a mixture of soil, water, and cement) to prevent further collapse and stabilize the ground. PUB announced a safety "time-out" to review similar sewer construction projects across Singapore to prevent recurrence.

The road was progressively reopened from August 2, 2025, after rigorous safety checks, including ground-penetrating radar scans to detect subsurface voids, confirmed the area was safe.

Public concerns and reassurances

Residents in nearby areas (e.g., One Amber condominium and landed properties) expressed concerns about the safety of their homes and roads. BCA conducted preliminary checks and confirmed that surrounding buildings were structurally unaffected. Members of Parliament (Goh Pei Ming and Gho Sze Kee) emphasized that stability and safety were priorities and that agencies were working to restore normalcy.

Similar sinkhole incidents in the past

Sinkholes are rare in Singapore but have occurred in the past, often linked to construction activities or underground pipe leaks. Similar incidents include:

• 2022: A sinkhole on Farrer Road due to tunnelling works.
• 2014: A cave-in on Upper Changi Road East near an MRT construction site.
• 2013: Multiple sinkholes, including one at Keppel Road caused by a burst water pipe.