The Great Recession was a period of marked general decline observed in national economies globally, i.e. a recession, that occurred from late 2007 to 2009. It was the most severe economic and financial meltdown since the Great Depression of the 1930s. The recession was caused by a combination of vulnerabilities that developed in the financial system, along with a series of triggering events that began with the bursting of the United States housing bubble in 2005–2012. When housing prices fell and homeowners began to abandon their mortgages, the value of mortgage-backed securities held by investment banks declined in 2007–2008, causing several to collapse or be bailed out in September 2008. This 2007–2008 phase was called the subprime mortgage crisis. The combination of banks unable to provide funds to businesses, and homeowners paying down debt rather than borrowing and spending, resulted in the Great Recession that began in the U.S. officially in December 2007 and lasted until June 2009, thus extending over 19 months. The Great Recession was notably severe in several respects, with real gross domestic product (GDP) falling 4.3 percent from its peak in 2007Q4 to its trough in 2009Q2, the largest decline in the postwar era. The unemployment rate, which was 5 percent in December 2007, rose to 9.5 percent in June 2009, and peaked at 10 percent in October 2009.