It shall be unlawful and a public nuisance for any operator of a railroad train in the Mount Washington and Highland Park areas of the City of Los Angeles between the intersection of Figueroa Street and Marmion Way up to and including the area at the intersection of Figueroa and Avenue 61, to blow or otherwise activate, or permit to be blown or activated, any horn or whistle when approaching any railroad crossing at grade, protected by automatic crossing gates, EXCEPT in the case of any emergency. (Amended by Ord. No. 150,410, Eff. 1/20/78.)