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 report, Goldman said "While we disagree with many of the conclusions of the report, we take seriously the issues explored by the subcommittee. We recently issued the results of a comprehensive examination of our business standards and practices and committed to making significant changes that will strengthen relationships with clients, improve transparency and disclosure and enhance standards for the review, approval and suitability of complex instruments." In another press release, Goldman claimed that they " did not have access to any special information that caused us to know that the U.S. housing market would collapse." They claimed they had no