Prosecutors have told the first day of the Enron trial the billion-dollar collapse of the US energy firm in 2001 was a simple story of greed and lies.
Ken Lay blames junior staff and insists he is innocent
Enron was a "time bomb" because former bosses Ken Lay and Jeffrey Skilling committed a giant fraud to cover up the state of its finances, lawyers claimed.
Defence lawyers countered that there was no conspiracy and Enron failed due to the "tragedy" of a cash crunch.
Both defendants deny charges including fraud and conspiracy.
Enron's collapse was the biggest corporate scandal in recent US history.
Enron collapsed in December 2001 after the revelation that an estimated $40bn (£23bn) of debts had been hidden in secret accounts to protect the firm's core balance sheet.
"This is a simple case," said prosecutor John Hueston in his opening statement. "It is not about accounting. It is about lies and choices."
"To the outside world, Enron appeared to be a picture of corporate success. Inside the doors of Enron, things were terribly wrong," he said.
Daniel Petrocelli, a lawyer representing Mr Skilling, said that there was "no evil" and "no conspiracy" that caused Enron to fail. Instead, the company collapsed because it could not get cash to fund its business.
"This is not a case of hear-no-evil, see-no-evil," said Mr Petrocelli. "This is a case of there was no evil."
'Others to blame'
Mr Lay, Enron's founder and former chairman, faces seven counts of fraud and conspiracy.
Mr Skilling , its former chief executive, faces 31 counts of fraud, conspiracy, insider trading and lying to auditors about Enron's financial position.
Jeff Skilling, right, with his defence lawyer Daniel Petrocelli
If convicted on all counts, the two defendants are likely to spend most of the rest of their lives in prison.
Mr Lay and Mr Skilling's defence is expected to be that they simply did not know about the giant fraud, which was instead carried out by more junior staff, led by former finance chief Andrew Fastow.
Mr Fastow struck a plea bargain with the authorities last year in return for a reduced sentence and is expected to give evidence against the two men.
Getting on with business
The case is being heard by US District Judge Sim Lake, who on Monday personally quizzed more than 100 potential jurors before picking the final 12, plus four reserves.
Defence lawyers had earlier failed in an attempt to persuade Judge Lake to move the trial away from Houston, Enron's hometown, fearing that remaining anger over the firm's collapse could harm jury independence.
About 4,000 people lost their jobs, the majority of whom worked in Texas, while many others saw their life savings disappear as a consequence.
Mr Lay said after jury selection on Monday that he was simply looking forward to the trial getting started.
"Now we can get on with the business of proving our innocence," said Mr Lay, who had arrived at court arm in arm with his wife Linda.