U.S. Bank National Association is trying to foreclose on the 21-story Chase South Tower in downtown Baton Rouge, claiming in a federal court lawsuit that the building’s owners haven’t made a loan payment since October.

U.S. Bank said Florida Street Holdings LLC is in default on a $21.5 million loan it obtained to buy the high-rise office building at 451 Florida St. Florida Street Holdings, which is based in Delaware and made up of five New York investors, obtained the loan in December 2007.

U.S. Bank filed its foreclosure suit April 19 in the U.S. District Court for the Middle District of Louisiana.

According to the lawsuit, as of March 1, the borrower has been past due on its monthly payments for the building since October. However, Florida Street Holdings made some payments since March 1 but remains in default. The lender said Florida Street owes $22 million in payments, fees and interest, plus attorney fees.

Florida Street had not filed a response to U.S. Bank’s lawsuit.

The case has been assigned to U.S. District Judge Shelly Dick.

The 21-story Chase South Tower has been open since 1967. Some of its tenants include Chase Bank, Albemarle, Taylor Porter and Ameritas Technologies. The building had been topped off by the Camelot Club, but the private club closed last month.

Follow Timothy Boone on Twitter, @TCB_TheAdvocate.