Sinkhole urban areas due to water main breaks or sewer collapses when old pipes give way. They can also occur from the overpumping and extraction of groundwater and subsurface fluids. Sinkholes can also form when natural water-drainage patterns are changed and new water-diversion systems are developed. Some sinkholes form when the land surface is changed, such as when industrial and runoff-storage ponds are created; the substantial weight of the new material can trigger a collapse of the roof of an existing void or cavity in the subsurface, resulting in development of a sinkhole. Sinkholes tend to occur in karst landscapes. Karst
2007 Guatemala City sinkhole 2007 Guatemala City sinkhole The 2007 Guatemala City sinkhole is a 100-metre deep sinkhole which formed in Guatemala City in 2007, due to sewage pipe ruptures. Its collapse caused the deaths of five people, and the evacuation of over a thousand. The sinkhole was created by fluid from a sewer eroding uncemented volcanic ash, limestone, and other pyroclastic deposits underlying Guatemala City. The hazards around the pipe have since then been mitigated, by improved handling of the city's wastewater and runoff, and plans to develop on the site have been proposed. However, critics believe municipal authorities have neglected needed maintenance