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
Wall Street and the Financial Crisis: Anatomy of a Financial Collapse Wall Street and the Financial Crisis: Anatomy of a Financial Collapse Wall Street and the Financial Crisis: Anatomy of a Financial Collapse is a report on the financial crisis of 2007–2008 issued on April 13, 2011 by the United States Senate Permanent Subcommittee on Investigations. The 639-page report was issued under the chairmanship of Senators Carl Levin and Tom Coburn, and is colloquially known as the Levin-Coburn Report. After conducting "over 150 interviews and depositions, consulting with dozens of government, academic, and private sector experts" found that "the crisis was not a natural disaster, but the result of high risk,