sinkhole

Most natural sinkholes happen in areas with large deposits of carbonate rocks, like limestone.

One worker on the site was suddenly pulled into a sinkhole when the bottom of the caisson blew out.

The inadvertent returns in the Mariner East II line created water quality issues in nearby wells, led to sinkholes in some areas, and spilled drilling fluid into sensitive environmental areas.

All it takes is a little agitation for the soil to liquefy and flow into the bottom of the caisson, creating a sinkhole that can easily swallow anything at the surface.