In case of emergency where there is actual and immediate risk of failure or collapse of a building or structure or the existence of defective equipment or service facilities such as to endanger life or health or such other condition as to require immediate action to make repairs necessary to prevent the occurrence of such failure or collapse or the occurrence of such danger and time available is not sufficient to allow the securing of a permit from the Chief Building Official as required by this Building Code, the person, firm or corporation required to perform such repairs may proceed to do so after having first notified the Chief Building Official of such fact without obtaining a permit as required by this Building Code. In case the Chief Building Official is unavailable, notice shall be given to the Backup Chief Building Official.
(‘74 Code, § 150.24)