Bangkok sinkhole: Soil entered metro tunnel due to damaged station ceiling, says governor
Sign up now: Get ST's newsletters delivered to your inbox
Follow topic:
BANGKOK – A section of a road in Thailand’s Dusit district near Bangkok’s Chao Phraya River collapsed on the morning of Sept 24, damaging nearby utilities and posing risks to commuters.
At around 7am local time (8am Singapore time), traffic police reported that the road surface in front of Vajira Hospital in Samsen Road had collapsed, causing a burst water pipe. The authorities shut down traffic to allow urgent repairs.
District authorities on the morning of Sept 24 announced the immediate closure of traffic from Vajira intersection to Sanghi intersection and the surrounding areas.
The collapse occurred near the construction site of the new Vajira Station MRT line, directly in front of Vajira Hospital.
Preliminary inspection revealed that the incident was caused by massive road subsidence, creating a crater measuring about 30m by 30m – slightly bigger than half an Olympic-size swimming pool – and 50m deep.
Two electricity poles fell into the hole. A pickup truck trapped at the sinkhole’s opening was recovered by rescuers, who were working to recover two other vehicles from the lower part of the sinkhole.
The pickup truck, which belongs to a construction team, had been positioned on the road to block the path of civilian traffic as the ground began to collapse. It was abandoned by the driver just before the ground sank more extensively.
Bangkok governor Chadchart Sittipunt on Sept 24 inspected the road subsidence. He explained that the collapse was caused by soil entering the underground metro tunnel at the junction between the tunnel and the station.
“When the station ceiling was damaged, soil above it flowed into the tunnel and the under-construction underground space, causing nearby buildings to subside. The side heading towards Sanghi Bridge remains stable, but the collapsed side has soft soil and lacks supporting structures,” the governor said.
The incident damaged a main water pipe and disrupted tap water supply along 31 roads in the capital, according to the Metropolitan Waterworks Authority.
The Mass Rapid Transit Authority of Thailand, which is responsible for the MRT construction project, has been tasked with assessing all damages and holding those responsible accountable. It has also ordered a temporary halt to the construction of the new line there.
The collapse continues to expand, affecting areas in front of Vajira Hospital and Samsen police station, and prompting the Metropolitan Electricity Authority to conduct urgent safety measures.
The hospital said all outpatient services have been suspended for two days, and that it will reschedule some 3,500 affected patients as soon as possible.
Thai Prime Minister Anutin Charnvirakul, who is also Interior Minister, ordered an urgent investigation into the incident, and requested the cooperation of engineering experts from various professional bodies and universities to help determine the cause of the collapse.
“This is a purely engineering matter. We will definitely find the cause,” Mr Anutin said, noting that the incident began when people saw water welling up from the road surface.
“The safety of the public has been secured, and there were no injuries or deaths,” he said after visiting the site.
Mr Anutin confirmed that while Vajira Hospital’s building remains structurally sound, the nearby five-storey Samsen police station was affected, with two or three of its foundation piles breaking.
All police officers and residents from nearby row houses were evacuated.
The incident caused severe congestion along Samsen Road, extending to the inbound Krung Thon (Sanghi) Bridge, where traffic stretched for several kilometres.
Officials from the Bangkok Metropolitan Administration and related agencies were working to stabilise the area and restore traffic as quickly as possible.
Timeline of the road collapse
7.13am: A massive sinkhole, about 50m deep, appears in Samsen Road in front of Vajira Hospital, in Dusit district, and continues expanding towards the hospital and Samsen police station. No injuries are initially reported.
7.24am: The subsidence spreads close to hospital buildings. The authorities begin evacuating patients and nearby residents from the affected area.
7.45am: Two electricity poles and a tow truck from Samsen police station fall into the sinkhole as the collapse widens further. Metropolitan Electricity Authority officials arrive at the scene to begin emergency work.
7.50am: Residents of nearby flats are instructed to evacuate the area.
8am: Bangkok governor Chadchart Sittipunt inspects the site of the road collapse in front of Vajira Hospital in Samsen Road. THE NATION/ASIA NEWS NETWORK
