The board of supervisors may, by a resolution incorporating such limitations and safeguards as may be deemed in the best interests of the county, provide that county officers and employees who are responsible for receiving and paying out money may be relieved of shortages in their accounts, where there is no proof of fraud or gross negligence in connection with the shortage and where the loss is not covered by insurance. If the board of supervisors after an investigation and report by the county auditor approves the coverage of such shortage, it shall be entered in its minutes and shall be a charge against the general fund of the county.