The only thing that should close the library is the building itself being blown to smithereens. Your emergency kits should suffice in rescuing you from any situation, with the exception of the building being blown to smithereens. If you and the building are blown to smithereens, you may officially close the library.
Every employee, of every library in the world knows this is true. An act of God could be occurring outside (or inside) and your director, provost, etc. will believe that it is essential that the library remain open. I have never understood this principle.
–Jane, duck and cover