Failure to properly maintain aging water and sewer systems sometimes manifests itself with the appearance of sinkholes, collapse of the surface into voids produced by erosion by leaking water. Often, however, there is no visible manifestation, simply a literal drain on the resources of the community. 
Natural sinkholes also occur, especially in areas underlain with limestone, which dissolves due to the action of flowing underground water forming caverns. They may also result from collapse of abandoned mines.
In 2007 a 330 foot sinkhole opened up beneath Guatemala City, killing two people and swallowing a dozen homes. It was believed to have originated with a ruptured sewer main aggravated by heavy rain.