Enron

Enron was an energy trading company that, for a time, represented one of the biggest corporations in the U.S. At the end of 2000, the company was worth more than $60 billion. Within a year, it would be worthless.

While the company ostensibly built its energy trading business, a group of company executives used tricky accounting to hide massive losses at the firm. The fraud allowed them to get rich on bonuses and stock options, which they supplemented with a number of shady side deals that further obscured the company's true financial situation and funneled millions of dollar to the execs.

The scandal was eventually exposed in 2001, when the executives were unable to mask the losses any longer. They attempted a massive write down, but as investors (and eventually authorities) looked closer, it became clear that much of the company's recent history of success had been a matter of accounting fiction. Enron eventually collapsed, filing for bankruptcy in early December, 2001.

At the time, it represented the largest bankruptcy in U.S. history (in a sign of the times, it would only hold that record for less than a year; WorldCom, another company brought down by massive accounting fraud, would take the worst-ever bankruptcy crown in 2002).

The pain from the Enron collapse was more than financial. There was a significant human toll as well. A former vice chairman, J. Clifford Baxter, killed himself in early 2002. Meanwhile, tens of thousands of employees lost their jobs and most lost at least a significant portion of their retirement savings as well.

The scandal eventually led to jail time for some of the responsible executives. The company's former CEO Kenneth Lay, who, at one time, had been on the short list to become Energy Secretary, was convicted of fraud-related charges in 2006. Jeffrey Skilling, a long-time company executive and another one-time CEO, and Andrew Fastow, the firm's former CFO, were also convicted of fraud in the aftermath of the scandal.

Fun fact: the Enron scandal inspired a Broadway play. Called simply "Enron," the show included song-and-dance numbers and people dressed in dinosaur heads. It lasted less than a month.