Bangkok, Sept. 24 -- Thai Prime Minister and Interior Minister Anutin Charnvirakul ordered an urgent investigation into a massive land subsidence that occurred in Bangkok earlier on September 24.

The collapse took place near Vajira Hospital on Samsen road, caused by soil erosion at the construction site of the new MRT Purple Line.

The large-scale underground project stretches from the Parliament through Sam Sen road, tunnels under the Chao Phraya River, and continues toward Suksawat. A 30-by-30 meter section of road in front of the hospital suddenly sank, forming a sinkhole up to 50 meters deep.

The incident struck at one of the most complex points along the route where the tunnel intersects with the future Vajira Hospital station. Soil ...