Here's what some agencies have said about their specific plans in case of a government shutdown.

The Social Security Administration tells its story in "History Of SSA 1993 - 2000."

http://www.washingtonpost.com/politics/federal_government/shutdown-uncertainty-generates-angst-and-rumors-among-federal-employees/2013/09/25/9aa1e2d4-2615-11e3-ad0d-b7c8d2a594b9_story.html