And the earth opened her mouth, and swallowed them up together with Korah, when that company died, what time the fire devoured two hundred and fifty men: and they became a sign. Numbers 26:10
Sinkholes are natural phenomenon. However, the Bible shows an instance when a sinkhole did not occur naturally but was a judgment from God upon the sins of certain men.
It occurred in this manner:
Several men grew angry with Moses, the prophet of God, and declared that they were as holy as he was. Jealous and assured of their own holiness, they rebelled against Moses' rule. This rebellion angered God and he caused the earth to open up underneath them.
This became a sign to all generations that however holy a group of people are --if God has chosen a minister above them all-- that that minister should be respected.