If it is shown that any municipality or other taxing district has been guilty of negligence which will amount to a breach of its duty to holders of special assessment warrants, such municipality or taxing district shall be liable in damages to the holders of the special assessment warrants. Such damages, however, shall be limited to the actual damages sustained by the warrant holder or holders as the direct and proximate result of such negligence. If the damage for negligence is predicated upon any act of the municipality or other taxing district which resulted in the loss of any special assessment lien upon real property, the measure of damages    shall be limited to the value at the time of trial of the property upon which the lien was lost over and above the amount of the general taxes delinquent against such property at the time that the county acquired title thereto. The face amount of the warrants involved in any action shall be considered only as a limitation of the amount which may be recovered in such action on said special assessment warrants.