First Liberty Building and Loan, a Newnan-based private lending firm operated by the Frost family, abruptly shut down this week, suspending all payments to investors and announcing it is cooperating with federal authorities as it winds down operations. In a notice posted to its website, First Liberty said it would no longer accept new investments or make bridge loans, and that interest payments on existing promissory notes and other investments were “indefinitely suspended.” The company also stated employees would not be taking calls or emails while it works with federal agencies to sort through its affairs. The announcement marked a...