"A sinkhole is a natural depression or hole in the surface topography caused by the removal of soil or bedrock, often both, by water. Sinkholes may vary in size from less than a meter to several hundred meters both in diameter and depth, and vary in form from soil-lined bowls to bedrock-edged chasms. They may be formed gradually or suddenly, and are found worldwide." - Wikipedia
I seem to be developing an irrational fear of sinkholes... I suspect my studies at seminary may be the cause. What's more terrifying, is that I have a growing suspicion that the only way to relieve the dread, is to stop fighting the fall.