WASHINGTON - May 5, 2010 - As a special panel delves into the financial crisis, the executives who led Bear Stearns Cos. before the big Wall Street firm's implosion two years ago are saying they did all they could to keep it afloat before it fell victim to an unstoppable run on the bank.

James Cayne, who was Bear Stearns' CEO until January 2008, and Alan Schwartz, who succeeded him for a few months, are to testify Wednesday before the bipartisan panel investigating the roots of the crisis.

The firm's collapse "was due to overwhelming market forces that Bear Stearns ... could not resist," Cayne said in his testimony prepared for the hearing.

Bear Stearns was the first Wall Street bank to blow up in the recent crisis, caught in the credit crunch in early 2008 and foreshadowing the cascading financial meltdown in the fall of that year.

Two of Bear Stearns' hedge funds failed in June 2007 as a result of bad bets on the subprime mortgage market, costing investors $1.8 billion and touching off the domino chain that brought the firm to the brink in March 2008.