Last night I noticed that water was leaking slowly from a vent in the walkout basement. I thought maybe condensation. Today I found out it was leaking pipes from above. Earlier today it was leaking enough to get the floor below wet, though that is now drying. My main concern is that by the vent there is now a brownish water spot that is about 4 inches wide and maybe a foot long. I worry about everything but my most recent worry is mold/structural damage. Do I need to have a professional come and fix the damage or for something that small can you just let it dry on it's own and not be at much of a risk for future issues? The plumbing issue is taken care of. Just the water I worry about. If needed, any idea what something like that would cost?