I work in a gun free zone
so I've not bothered with a CCW permit.
I *do* have lots of improvisable weapons around my desk... and a quick shot out a mostly-hidden hallway to the parking lot... where I will most times be able to arm up. Should it come to that, I'll be staying at/in/near my car with something quickly available in the car - ie open trunk, load it, leave it in the case in the trunk, close trunk. Have no dreams of being a hero, don't wanna be a hero, don't get paid to be a hero, but dammed if I'll leave myself defenseless when I don't have to.
FWIW the only really nasty event we've had on campus a guy walks into his soon-to-be-ex's office and cuts her throat, dropped the knife, and ran out. Got on the interstate and headed north, was caught just after he crossed into Georgia.