/i'm willing to bet you a large sum of imaginary money that it is fine. Just tune it. If it's a floating trem and you broke a string, then change the string lol.
What guitar is it?(model, colour is unimportant

)
Are you sure it's not just a broken string somewhere or other? Guitars don't normally break if you drop them. Well, in my experience anyway. A bassist I know crashed (rolled) his car, with bass on the backseat, and it was fine. Still is fine. It falls over regularly lol.
Have one of the strings sort of frayed apart at the bridge? Re-string it, if it's still a problem, then it might be screwed.
Pics?