Every person or corporation having occasion to place any obstruction in any street or alley or to make any excavation therein under the provisions of this chapter, is responsible to any one for any injury by reason of the presence of such obstruction or excavation in the public highways and is also liable to the City, in the event that the City is held responsible for any accident claims or otherwise arising out of the presence of any such obstruction or excavation in said public highways. (Ord. 1700 § 9, amended, 1971)