A section of Samsen Road in front of Vajira Hospital in Bangkok subsided on Wednesday morning, forming a huge sinkhole about 20 metres deep. No injuries were reported.
The incident occurred at 7.13am, with the sinkhole estimated to be 30 metres wide and 30 metres long. It formed immediately above the under-construction Vajira Hospital train station.
The collapse occurred when a tunnel housing a subway track caved in, causing the soil above to shift quickly and slide into the underground station, said Bangkok governor Chadchart Sittipunt. Broken pipes let water pour into the hole, worsening the slide.
Officials were monitoring a 100-metre radius around the site, as the sliding and subsidence continued well into the afternoon.
Two electricity poles and a police vehicle fell into the hole after the collapse. Staff from the Metropolitan Electricity Authority (MEA) were on-site working.
Traffic between the Vajira and Sanghi intersections was closed for safety reasons, the Dusit District Office said.
A year to repair
Prime Minister Anutin Charnvirakul told reporters after inspecting the scene that repairs to the tunnel and road would take at least a year.
The matter would be discussed as a matter of urgency when his new cabinet meets for the first time on Wednesday evening, shortly after taking the oath of allegiance before His Majesty the King, he said.
Nearby residents saw water seeping from the ground moments before the collapse, Mr Anutin said.
A major inquiry would be set up, headed by the Mass Rapid Transit Authority, he said.
“We can’t say what caused this yet. There’s certainly been a mistake made, but this is all about engineering, and we must find out the cause,” said Mr Anutin, who is an engineer by training and whose family runs the country’s second-largest builder, Sino Thai Engineering and Construction.
“There’s no danger to people’s lives, that’s all under control,” he added. (Story continues below)
Authorities say the Samsen Police Station could be in danger because of damage to its pilings. (Photo: Pornprom Satrabhaya)
Police station at risk
One major concern is the safety of the five-storey Samsen Police Station. The subsidence had damaged a couple of its foundation piles.
The hospital is considered safe because of underground foundation walls, Mr Chadchart said.
Outpatient services at the state-run hospital have been suspended, and about 3,500 inpatients were evacuated from nearby buildings. An initial report indicated that hospital structures were not damaged.
Residents of nearby apartments were also instructed to evacuate.
The area was previously closed due to the construction of the Mass Rapid Transport (MRT) Purple Line (Tao Poon and Rat Burana extension). (Story continues below).
Deep trouble: Engineers and inspectors take a closer look at the sinkhole, which is about 20 metres deep. (Photo: Bloomberg)
The sinkhole swallowed a car belonging to a police officer. (Photo: Bloomberg)
Authorities have cut off water and electricity to control the situation and prevent further risks. Other urgent measures ordered included sealing the tunnel leak, assessing the safety of surrounding buildings, monitoring soil movement and managing traffic in the area.
Mr Chadchart said another critical concern was rainfall, which could cause more soil to flow into the openings. A team was set up to evaluate and respond to rainfall scenarios.
Vajira Hospital has suspended outpatient services for two days. Inpatient services remained operational. Other hospitals under the Bangkok Metropolitan Administration were available for outpatient cases during this period, he said.
Meetings would be held at noon and 6pm daily to monitor the situation, the BMA said.
