Duck and cover!

You do the most noble thing you possibly can, and cower under your desk in the hopes you won't be seen. It actually seems to work - the zombies are too busy with everyone else, screaming and hollering about and beating on windows and walls, to notice you under there. Actually - the one from before only went for the supervisor, and not everyone else. Everyone else was being quiet and the supervisor was making a lot of noise. You hypothesize that the infected are probably blind, and find targets by sound alone. Actually, their eyes look like they're blind, too, so that makes a lot of sense.

You endeavor to continue hiding and to stay quiet for as long as possible until you can find a chance to escape.