It's raining bird poo

I don't remember much. I remember walking through an old run-down building. I was on an elevator going somewhere (dunno where) and The elevator roof was dripping water. As soon as I figured out it was dripping on me, I took a step over and then it started to downpour. I managed to get off the elevator shortly afterward. I also remember there were birds flying around. I never saw or heard the birds, but I knew when I thought they were near, I would duck and cover my head with my hands so they wouldnt poop on me.