The incident occurred when an overpass collapsed onto vehicles on Bang Na-Trat Road, km 34, in front of the Nam Thai Market, Bang Bo District, Samut Prakan Province, on Thursday (December 18).
There are reports of injuries, with people trapped inside the vehicles, and a gas leak at the scene.
Rescue teams are working to save those trapped.
According to a Facebook post by "NAKON45 Anwat Pho-Amphai," the incident involved a pedestrian bridge collapsing onto vehicles, trapping individuals inside.
The Ruamkatanyu Foundation is leading the rescue, providing critical aid while simultaneously managing the gas leak.
FM91 Trafficpro radio station reported that by 9.15am, severe congestion was building up on the main lane of the inbound section of the road near the incident site.
The overpass collapsed onto a truck and a pickup truck, blocking the main lanes inbound. Three individuals were injured and trapped inside their vehicles, and rescue operations are ongoing.
Motorists are advised to avoid the area if possible to prevent further delays.
Preliminary reports indicate that a dump truck struck an overpass beam, causing it to fall onto two vehicles on Bang Na-Trat Road, km 34, inbound to Bangkok.
There are casualties and injuries.