South Carolina's embattled top accountant will resign next month after a $3.5 billion accounting error in the year-end financial report he oversaw. A copy of the resignation letter from Comptroller General Richard Eckstrom indicates he'll leave the post on April 30. The letter was dated Thursday and obtained by The Associated Press. Revelation of the blunder last month brought mounting scrutiny to Eckstrom, who has held the job for 20 years. House lawmakers called for an impeachment inquiry. The Senate panel investigating the error issued a damning report last week that suggested Eckstrom resign or face removal “for willful neglect of duty.”