Taichung, Taiwan, 1999: earthquake-opened sinkhole filled with molasses spilled from nearby storage tanks.
Sinkholes tend to appear suddenly, and while particular regions are famously prone to sinkholes they happen all over the world. Sinkholes form when the bedrock or soil underneath subsides, forcing the topsoil (or in many cases concrete) to collapse. They can be exceptionally large (several hundred meters in diameter and depth) and can swallow everything directly above. They’ve been known to “swallow” cars, homes, businesses, and other structures. (Pics)