In February 2007, a very large, deep circular hole with vertical walls opened in northeastern Guatemala City (), killing five people. This sinkhole, which is classified by geologists as either a "piping feature" or "piping pseudokarst", was  deep, and apparently was created by fluid from a sewer eroding the loose volcanic ash, limestone, and other pyroclastic deposits that underlie Guatemala City. As a result, one thousand people were evacuated from the area. This piping feature has since been mitigated by City Hall by providing proper maintenance to the sewerage collection system and plans to develop the site have been proposed. However, critics believe municipal authorities have neglected needed maintenance on the city's aging sewerage system, and have speculated that more dangerous piping features are likely to develop unless action is taken.