"It's frustrating," agreed Editha Heberlein, 56, of Springfield, Va. "Hopefully Congress can get their act together just for the sake of everybody."In Washington, visitors to the National Mall found locked doors, black metal barricades and yellow caution tape blocking entrances to tourist attractions just hours after the shutdown. Fountains at the World War II Memorial were shut off. "Why the heck does this have to be closed?" said Deb Cavender, 44, of Ames, Iowa, as she and her husband were making their way toward the memorial. It turns out an institution as massive as the federal government takes some time to grind to a total halt: Many federal workers were being permitted to come in Tuesday to change voicemail messages or fill out time cards. But after that, they were under strict orders to do no work, even check their email. With no telling how long the standoff will last, even programs not immediately affected could run out of cash. Barbara Haxton, executive director of the Ohio Head Start Association, said its preschool learning programs would be in jeopardy if a shutdown lasted more than two weeks. Automatic budget cuts in March meant nearly 3,000 children lost access to services and there could be dire consequences if the budget standoff drags on, she said. "It's not as though this is a throwaway service. These are the poorest of the poor children," Haxton said. "And our congressman still gets his paycheck. His pay doesn't stop and his health insurance doesn't stop." ___ Associated Press writers Joe Frederick in New York, Jessica Gresko, Brett Zongker and Joan Lowy in Washington, and Amanda Lee Myers in Cincinnati contributed to this report.