If any wall, projecting, sale or roof sign is suspended over a public street or property, or if the vertical distance of such sign above the street is greater than the horizontal distance from the sign to the street property line or parapet wall and so located as to be able to fall or be pushed onto public property, then the owner of such sign shall keep in force a public liability insurance policy approved by the Solicitor in the amount of fifty thousand dollars ($50,000) for injury to one person and one hundred thousand dollars ($100,000) for injury to more than one person, and twenty-five thousand dollars ($25,000) for damage to property; such policy to indemnify such owner and the City and its officers, agents and employees for all damage suits or actions of every nature brought or claimed against the owner for or on account of injuries or damages to persons or property received by any person or persons through any act or omission or negligence of such owner and/or the City and their respective servants, agents or employees regarding such sign, and cause a certification of such insurance to be issued to the City.