While performing the necessary work on private properties, the Safety-Service Director and/or duly authorized City employees shall observe all safety rules applicable to the premises established by the company, and the company shall be held harmless for injury or death to the City employees, and the City shall reimburse the company for loss or damage to its property by the City employees and shall indemnify the company for personal injury or property damage asserted against the company and growing out of the gauging, inspection, observation and sampling operation, except as such may be caused by negligence of the company to maintain safe conditions.