On 19 September 1955, "San Luis", "San Juan" and "Entre Rios" supported cruiser ARA Nueve "de Julio" when the latter shelled and destroyed fuel depots at the port of Mar del Plata, in the course of the Revolucion Libertadora. The destroyers' fire kept at bay a group of armed civilians and soldiers attempting to storm the local naval base. Some civilian property was damaged. The destroyer force also shelled the headquarters of the Army Antiaircraft School, north of the city, some hours later.