Whenever any nuisance (a) constitutes or is deemed to be an imminent or immediate danger to the public health or safety, or (b) exists on public property, the proper City officer shall cause such nuisance to be summarily and immediately abated and removed, regardless of any five (5) day or other time period specified by notice to the person responsible therefor; provided, however, that in situation (a) above, such officer shall have first applied for and obtained the written permission of the Mayor for such summary abatement. (1994 Code)