Any such dangerous building in the City is hereby declared to be a nuisance, and it shall be unlawful to maintain or permit the existence of any dangerous building in the City, and it shall be unlawful for the owner, occupant or person in custody of any dangerous building to permit the same to remain in a dangerous condition or to occupy such building or permit it to be occupied while it is or remains in a dangerous condition. (1979 Code Ch. 18, Art. III, §§1, 2)