Every tree, shrub, plant, fence, wall or other structure, or any branch, limb or part thereof, whether located upon public or private property, which is, or is likely to become, dangerous to the public by reason of the fact that it is diseased or encroaches upon or overhangs or may fall upon any public street, alley, sidewalk or other public place or which encroaches upon or is likely to damage any street, alley, sidewalk or other public place or any sewer or water conduit or any public drain or work is a public nuisance.
('81 Code, § 12.20.030)