WASHINGTON — The head of the Federal Deposit Insurance Corp. has warned that the fund insuring Americans’ bank deposits could be wiped out this year without the money the agency is seeking in new fees from U.S. banks and thrifts. FDIC Chairman Sheila Bair acknowledged, in a letter to bank CEOs, that the new increased fees and hefty emergency premium the agency voted to levy last week will bring a “significant expense” to banks, especially amid a recession and financial crisis when their earnings are under pressure. “We also recognize that assessments reduce the funds that banks can lend in...