Chained up pit-bull near my house please help?

there is a neighbor across from me who has a pit bull. everyday i see him tied up in a corner and when i p by walking my dogs, he starts to whimper like crazy. it makes my heart sink and saddens me to see him in those conditions. hes like that for nearly all day and spends most of the time crying. idk what to do. should i call a police or an animal agency. please help i feel really bad for the pitbull.