Written notice of the hearing shall be mailed by first class mail, at least twenty (20) days before the date of the hearing to all owners of property within, contiguous to and directly across the street from such area proposed to be rezoned or redistricted to the address of such owners appearing on the County Auditor's current tax list or the Treasurer's mailing list and to such other list or lists that may be specified by Council or Planning Commission for this hearing. The notice shall contain the same information as required of notices published in newspapers as specified in this chapter. Failure to notify adjoining property owners shall not invalidate any actions taken.