Every week after pre-school, Jack walks here to the National Zoo to watch the elephants.Jack’s nanny, Kim Hazelton, doesn’t know what they'll do if a government shutdown closes the zoo.“I’m sure that it would be a total disaster every single day because that’s the first thing he asks for. He wants to come and see the animals," said Hazelton.Should a shutdown occur, none of these people would be seen on the sidewalk here at the zoo.Only essential zookeepers would be allowed in, to feed and take care of the animals.The National Zoo is part of the world’s largest museum complex - the Smithsonian Institution, which is funded by the government.Entry is free - but the Smithsonian relies on concessions for extra money, and they - and the museums - will be closed during a shutdown. The Smithsonians' Linda St. Thomas.“It will be tough for visitors, particularly ones who don’t check in advance and just come and see a sign on a door," said St. Thomas.Like the shutdown in the mid 1990s, work would continue on national security, air traffic control, food safety, in banking and prisons.But no visa or passport applications would be processed. There would be no new clinical research.The national parks would close, and millions of tourists would be shut out.