Woodmen of the World Life Insurance Society is suing U.S. Bancorp (USB) for allegedly exposing Woodmen to $47 million in losses through risky investments in mortgage-backed securities. Woodmen is a Nebraska-based fraternal society that issues life insurance policies to members. The case was filed in Delaware, the state of U.S. Bancorp's incorporation. A spokesperson for U.S. Bancorp, the parent company of U.S. Bank, said, "U.S. Bank believes strongly that it acted properly in the management of its customer's portfolio. It performed its services in accordance with its described duties, and U.S. Bank will continue to vigorously defend the litigation." The lawsuit alleged U.S. Bank breached its fiduciary duty to Woodmen of the World when managing a Trust Woodmen heavily invested in, according to court records. The plaintiff claims U.S. Bancorp never informed Woodmen of the World that commercial paper held in the trust fund was backed by subprime and Alt-A mortgage-backed securities. The plaintiff alleges the bank "held those assets until it was too late for Woodmen to obtain cash redemption of its investment" in the fund. Woodmen of the World writes in the complaint, "[o]n the surface this case involves complex and cutting edge securities, transactions and entity structures, but deep down the tale of wrongdoing in this action is as simple and old-fashioned as a frontier stagecoach heist." The case mirrors several other high-profile MBS securities lawsuits, including  insurer Allstate's claim against JPMorgan Chase (JPM) and subsidiaries Bear Stearns and Washington Mutual. Allstate  accused the businesses earlier this month of fraudulently selling more than $750 million in residential mortgage-backed securities backed by toxic loans to the insurer. Allstate also sued Credit Suisse for failing to disclose the toxic nature of the underlying loans within $231 million of  mortgage-backed securities the insurer purchased. Write to Kerri Panchuk.