No person shall engage in the business of operating taxicabs, or operate taxicabs for the transportation of persons for hire within the City, or permit taxicabs to be operated, until the applicant for a license deposits a certificate of liability insurance with the Mayor for each such taxicab for which a license is desired. The insurance must be acceptable to and approved by the Director of Law, indemnifying the applicant in the sum of one hundred thousand dollars ($100,000) for injury to one person, three hundred thousand dollars ($300,000) for injury to more than one person, and fifty thousand dollars ($50,000) for property damage in any one accident, through the operation of the taxicab for which a license is applied. The policy shall contain a clause obligating the surety or insurance company writing the policy to give ten days written notice to the Mayor before cancellation of the policy. Upon the lapse, expiration or termination of the policy and insurance, the license issued hereunder shall expire.