The Bangkok Metropolitan Administration closed Gesagomon Bridge in Dusit district for repair for five days from Monday after its embankment collapsed late Sunday night.
Bangkok governor Chadchart Sittipunt said at the site on Monday morning that the embankment collapsed during the construction of the new embankments of the Prem Prachakorn Canal under the bridge and the dredging of the canal.
He advised motorists to avoid Amnuay Songkhram Road which leads to the site.
The collapse reportedly occurred at about 9pm on Sunday, a few hours after local people spotted big cracks on the road surface in the area. The governor said that no cars drove into the big hole.
An official told the governor that the embankment initially subsided and cracked a water main. Water from the main then flooded the foundation of the bridge embankment and caused the collapse.