Enron was once the sixth largest energy company in the world but collapsed in 2001 due to widespread corporate fraud. Most top executives were convicted for inflating the company's earnings and profits through deceptive accounting practices. Thousands of employees lost their life savings and retirement funds when Enron stock became worthless as the fraud was revealed. The collapse of Enron resulted in the largest bankruptcy in U.S. history at that time and led to new laws and regulations to increase transparency and protect investors.