In all contracts with the city for paving or grading streets, for constructing sewers, for laying water pipes, and for building and repairing bridges and culverts or for doing any work whatever, where-by accidents or injuries may occur in consequence of any neglect or carelessness on the part of the con-tractor, a covenant, or condition shall require the contractor to place and maintain a good and sufficient fence, railing, or barrier around the same in such a manner as to prevent accidents and to keep upon such fence, railing, or barrier, suitable and sufficient colored lights during the entire night. Also, the contractor shall keep and save the city harmless and indemnified against all loss and damage which may be occasioned by reason of any negligence or carelessness in the manner of doing such work. In addition thereto, contractor shall carry worker's compensation insurance, public liability insurance naming the city as an additional assured in limits of not less than $100,000 for any one person and $500,000 for any one accident, property damages insurance not less than $50,000, and an indemnifying bond with a reputable stock insurance company indemnifying the city against all loss caused by damage to its streets, water, or sewer mains in an amount not less than $10,000.
(`79 Code, § 33.015)