▁second ▁assault ▁on ▁ 3 1 ▁March ▁resulted ▁in ▁the ▁capture ▁of ▁Le ▁Roc ▁No ir , ▁but ▁the ▁Red oute ▁Ru in ée ▁held ▁out . ▁The ▁off ensive ▁of ▁ 2 3 – 3 1 ▁March ▁" failed ▁miser ably ". ▁ ▁By ▁late ▁April ▁the ▁Red oute ▁Ru in ée ▁was ▁g arrison ed ▁by ▁a ▁pl ato on ▁of ▁forty - six ▁es pl or atori - ard iti ▁of ▁the ▁ 4 th ▁Regiment ▁under ▁Antonio ▁Ross itto . ▁The ▁ch asse urs ▁al p ins ▁attacked ▁the ▁fort ▁on ▁the ▁night s ▁of ▁ 2 7 / 8 ▁and ▁ 2 8 / 9 ▁April ▁and ▁there ▁was ▁serious ▁fighting . ▁On ▁the ▁morning ▁of ▁the ▁ 2 9 ▁April , ▁De ▁Fel ice ▁ordered ▁all ▁his ▁positions ▁on ▁French ▁soil , ▁include ▁the ▁Red oute ▁Ru in ée , ▁be ▁abandoned . ▁That ▁day ▁the ▁French ▁occupied ▁the ▁fort . ▁It ▁was , ▁along ▁with ▁the ▁Roc ▁de ▁Belle face , ▁also ▁occupied ▁that ▁day , ▁the ▁last ▁pieces ▁of ▁French ▁soil ▁under ▁Italian ▁occupation . ▁ ▁The ▁retre at ▁of ▁the ▁It ali ans ▁to ▁their ▁own ▁territory ▁was ▁deliber ately ▁slow , ▁at ▁the ▁suggestion ▁of ▁Adam , ▁so ▁as ▁to ▁d eter ▁the ▁French . ▁It ▁was ▁complete ▁by ▁the ▁time ▁the ▁S urr ender ▁of ▁Cas erta ▁took ▁effect ▁on ▁ 2 ▁May . ▁The ▁ 4 th ▁Al p ini ▁Regiment ▁surrender ed ▁to ▁American ▁forces ▁in ▁A osta ▁on ▁