Sinkholes

A sinkhole is a depression in the ground that has no natural external surface drainage. Basically this means that when it rains, all of the water stays inside the sinkhole and typically drains into the subsurface.
A rock is an aggregate of one or more minerals; or a body of undifferentiated mineral matter. 
There is no database of sinkhole collapses for the United States, so these data are unavailable. Some individual state geologic surveys track reported collapses within their state.
Sinkhole damages over the last 15 years cost on average at least $300 million per year. Since there is no national tracking of sinkhole damage costs, this estimate is probably much lower than the actual cost.Learn More:
Sinkholes are just one of many forms of ground collapse, or subsidence.
A sinkhole is a closed natural depression in the ground surface caused by removal of material below the ground and either collapse or gradual subsidence of the surface into the resulting void.
There are some very large, ancient, ‘inactive’ sinkholes in some areas of the U.S. that are thousands of years old. Alabama claims to have the largest recent collapse sinkhole.