(A) When, in the opinion of the Chief Building Official, there is actual and immediate risk of failure or collapse of a building or structure or any part thereof, or the existence of defective equipment or service facilities such as to endanger life or health, or when any structure or part of a structure has fallen or failed, and the use or occupancy of the structure, equipment, service facility, or equipment or part thereof would, in his opinion, endanger life or health, he is authorized and empowered to order and require the occupants and inmates to vacate the same, or to cease, desist, and refrain from the use or operation of the building, structure, equipment, service facility, or part thereof which is deemed dangerous. If such order is made, he shall cause to be posted a notice reading:
“This (building) (and) (equipment) is unsafe and its use or occupancy or operation is prohibited by law.”
It shall be unlawful for any person thereafter to enter, use, or operate such structure, equipment, service facility, or part thereof, except to repair or demolish.
(B) The Chief Building Official shall also cause such work to be done as may be necessary to render such structure, equipment, service facility, or part temporarily safe with regard to passersby and adjacent properties, as well as occupants, pending vacation and repair or demolition, whether or not he has previously issued any order of vacation thereof. In lieu of attempting to make such structure or part temporarily safe for passersby and adjacent properties, he may, when necessary for the public safety, temporarily close such adjacent properties and any affected sidewalks, streets, and other public ways and areas, and prohibit the use thereof. In causing any such work to be performed, he shall employ or engage such labor and use or purchase materials as may be necessary to accomplish the same as expeditiously as possible.
(‘74 Code, § 150.59)