Bernie Madoff, the mastermind behind the largest Ponzi scheme in history, has died in prison, AP reported citing a source. It said Madoff, 82, died at the federal medical center in Butner, North Carolina, from natural causes. He had an end-stage renal disease and other medical conditions. In 2009, Madoff pleaded guilty. He was sentenced to 150 years in prison and forced to forfeit $170 billion.