CNBC presents a series of reports looking back One Year Later: The Month That Shook The World."

As part of the special series, CNBC presents 1 Year Later: Reflections from the Street -- Maria Bartiromo sits down with the key players to get a first hand account of their role in the events of last September and the how the financial system has changed over the last year.

Since 2001, easy credit, relaxed regulations, sub-prime mortgages, and exotic securities had led to a booming, post-9/11, U.S. stock market and economy. The rewards were big and the risks ignored. Then, the housing bubble began to burst in 2007 and the dangers, and the cracks in the system, started to appear. It all came to head in September 2008 as financial markets around the world plummeted, big banks went under, and the economy collapsed.

September marks the one-year anniversary of "The Month That Shook the World." All month long CNBC examines how the biggest financial crisis since the Great Depression has changed our economy, the markets and the world. From unprecedented government intervention to a shrinking Wall Street to spiraling unemployment, all have their roots in last fall's financial meltdown. CNBC looks back at the crisis, reports on how the market and economy are doing now, and debates where it is headed.