Sinkholes ⚫ Measures in place to manage risk during construction

We refer to Mr Desmond Cheng's letter "Take steps to prevent sinkholes caused by human activity" (Sept 6).

- Tan Chun Yong

Sinkholes can occur when the earth beneath the surface is eroded, typically by water, resulting in underground voids or cavities. Sinkholes may be caused by underground tunnelling or excavation works, either directly or through soil erosion associated with these works.

Naturally occurring sinkholes are usually formed by the erosion of soluble carbonate rocks, including limestone and dolomite.