The collapse occurred at about 7am near the construction site for the planned Vajira station on a new underground rail line. Bangkok Governor Chadchart Sittipunt said soil had entered the underground works at the junction between a tunnel and the station after part of the station ceiling was damaged. The movement of earth into the excavated space caused the road above to give way, he said. A ruptured water main then added to the instability.
The crater pulled down electricity poles and several vehicles as it widened. One pickup truck, which had been used by a construction team to block civilian traffic when the road began sinking, was recovered from the edge. Emergency crews were also working around other vehicles lower in the hole. Fallen power infrastructure created an additional safety risk, while the broken pipe interrupted water service on 31 roads.
Vajira Hospital suspended outpatient services for two days and said about 3,500 appointments would need to be rearranged. Officials said the hospital building itself remained structurally sound. The nearby five-storey Samsen police station was affected, however, with damage reported to foundation piles. Police personnel and residents of adjacent row houses were moved out as a precaution.
No injuries or deaths were reported. Prime Minister Anutin Charnvirakul, who also served as interior minister, visited the area and ordered an urgent investigation involving engineers from professional organisations and universities. He described the cause as an engineering issue that required a formal determination.
The Mass Rapid Transit Authority of Thailand was directed to assess the damage and construction on the line at the site was temporarily halted. City and utility teams focused on stabilising the ground, isolating hazards and restoring services. The incident also caused severe congestion along Samsen Road and approaches to the Krung Thon Bridge as closures diverted traffic through the surrounding district. Officials warned that the immediate priority was to plug and secure the void before more surrounding material could be drawn into it. The road failure also demonstrated how an underground construction problem could quickly cascade through surface infrastructure. In this case, soil movement was followed by a broken water main, lost road support, fallen electrical equipment and disruption to a major public hospital. Each element had to be addressed while the ground remained unstable.
