Around 7 a.m. on 24/9, a sinkhole approximately 30 meters wide and 50 meters deep suddenly appeared on the road outside Vajira Hospital and Samsen Police Station in Dusit district, central Bangkok, Thailand.

Bangkok Governor Chadchart Sittipunt later explained that the sinkhole emerged near the construction site of a two-way subway tunnel for the Purple Line extension, which will connect western suburbs with Dusit district. The tunnel, 6.5 meters in diameter, lies 30-35 meters underground.

The sinkhole was caused by water leaking from a burst pipe at a weak point where the tunnel connects to the station. "The broken water pipe caused water to erode the soil beneath the road, leading to the incident," Suriyachai Rawiwan, director of the Bangkok Metropolitan Administration's Disaster Prevention and Mitigation Department, said.

Governor Chadchart stated that city authorities cut off the water supply to the area after the road collapse and inspected surrounding structures.

The sinkhole is less than 3 kilometers from Dusit Palace, a residence of the Thai Royal Family. Several cars and utility poles fell into the chasm. While no casualties were reported, the incident disrupted public services in the area.

By 3 p.m. that day, further subsidence was observed. Channel 8 reported the road had sunk an additional 2 meters, raising concerns about the safety of the nearby Samsen police station. Local officials are assessing the structural stability of buildings near the sinkhole, especially the hospital and police station.

Governor Chadchart established a command center at the Dusit district office to coordinate and oversee the response, according to the BBC. Authorities are concerned that weather conditions, especially rain, could worsen the ground subsidence and cause further collapses. They have instructed the Bangkok Drainage Department to prepare pumps in anticipation of heavy rain forecast for 28/9-29/9.

Large sinkhole on a road in Bangkok, Thailand on 24/9. Photo: *AFP*

Thai Prime Minister Anutin Charnvirakul visited the site, expressing concern about the situation and ordering the evacuation of people in at-risk areas to safety. He estimated that repairs to the collapsed tunnel would take about a year.

The Mass Rapid Transit Authority of Thailand (MRTA), which is constructing the subway extension, has not commented on the incident. The Bangkok Expressway and Metro Public Company Limited (BEM), which operates the Purple Line, stated it is not involved in the tunnel expansion project.

Thanh Tam (Thaiger, AFP, BBC)