A gigantic sinkhole formed May 31 in Guatemala City during heavy rainfall from tropical storm Agatha, which killed at least 146 people in Central America. The hole, reportedly more than 200 ft deep, swallowed a three-story building and most of an intersection. A similar but smaller sinkhole last year in the same vicinity was blamed on faulty sewer lines. City residents speculate that faulty wastewater treatment infrastructure triggered the latest geotechnical breach. The tropical storm swept ashore two days after a volcanic eruption. The first torrent ashore from the Pacific Ocean this year, Agatha created mudslides throughout the region that
Arch dams, classically curved monoliths situated in narrow valleys, are not as common as other types of dams, such as embankment dams and gravity dams. ENR takes a look at some of the biggest arch dams in the world, both completed and under construction.