Six years after the collapse of the country's biggest health care finance company, a trial is nearing for five executives accused of a $1.9 billion fraud that helped bring National Century Financial Enterprises down in 2002. Two former owners of National Century and three former executives facing charges that they conspired to defraud investors by diverting money from investors' funds for improper uses, fabricated data in investor reports, and moved money back and forth between accounts to conceal investor fund shortfalls. The government expects to call 45 witnesses during the trial, which is expected to last six to eight weeks.