The collapse of the nation’s housing market and subsequent mortgage mess that has bedeviled Wall Street for nearly a year cost Stanley O’Neal his job at Merrill Lynch & Co. Ditto for Charles Prince at Citigroup Inc.

Charles Prince steps down at Citigroup, which confesses that as much as $11 billion of additional losses may be coming. The sub-prime mortgage crisis claimed its second Wall Street chief executive in less than a week on Sunday as the embattled head of Citigroup Inc. stepped down. The nation's largest banking company warned it might also suffer a whopping $11 billion of additional mortgage-related losses.

First, it was Merrill Lynch's Stan O'Neal. Now, the sub-prime crisis is expected to cost Charles Prince his job. Citigroup Inc. Chief Executive Charles O. Prince is expected to resign this weekend, the Wall Street Journal said, as the widening sub-prime mortgage crisis deals a final blow to a reign long under attack.