WASHINGTON, Oct. 12 (UPI) -- The Smithsonian museums and research centers, along with the National Zoo, closed to the public Sunday for the first time during the federal government shutdown and are likely to remain closed until Congress reaches an agreement over national funding. Though the shutdown officially began Oct. 1, outside funds from donations and endowments allowed a brief extension. Now, its administrators said, the Smithsonian complex must cease public operations until a budget deal.