The bond shall be conditioned upon the payment to the City of any costs incurred by the City in completing the required work or in employing a private contractor to complete such work. Whenever the Director of Public Works finds that a default has occurred in the performance of any term or condition of work authorized by a permit, he shall give written notice of such default to the principal and surety of the bond. Such notice shall state the work remaining to be done, the estimated cost of completion and the time estimated by the Director of Public Works to be necessary for the completion of the work. After receipt of such notice, the principal or the surety must, within the time specified, either complete the work satisfactorily or deposit with the City an amount equal to the Director of Public Works’ estimate of the completion cost, plus an additional sum equal to 25 percent of such cost. (Ord. 1205 § 2, 1969; prior code § 27.402(3)).