had power restored in Argentina; north of Río Negro, coastal cities and the metropolitan areas of Uruguay also had power restored, as confirmed via Twitter by Uruguay's government-owned power company UTE. By the evening, it was announced that power had been restored to 98% of Argentina. By 17 June, it was confirmed that power had been restored to most of Argentina and Uruguay. Macri promised a full investigation. Citing official sources, Argentine media reported that the outage was linked to a failure in the transmission of electricity from the Yacyretá hydroelectric dam. Impact Because the distribution of drinking water was affected by the power outage, Agua y Saneamientos Argentinos, one of Argentina's biggest water companies, warned people without power to limit their use of water. The blackout had an impact on local gubernatorial elections taking place in Argentina, where the lack of power forced voters to fill out ballots in the dark, using their mobile phones as flashlights. In some regions of the country, the elections were postponed by authorities. Medical patients who were dependent upon home equipment were urged to attend local hospitals, where similar devices were still operational, as they were powered by backup generators. Investigation Investigations into the cause of the outage are being undertaken by both Edesur and the Argentine government. An independent energy expert in Argentina attributed a role in the blackout to "systemic operational and design errors" in the country's energy infrastructure. Argentine Energy Secretary Gustavo Lopetegui said it was unlikely to have been caused by a cyberattack. Preliminary reports suggested that the blackout likely originated from a fault in a 500 kV circuit from the municipality of Colonia Elía to Belgrano, a suburb of Buenos Aires. A second 500 kV circuit from Colonia Elía to Mercedes subsequently tripped under automatic action; the cause of that trip is still under investigation. A third 500 kV line from Colonia Elía to Nueva Campana was out of service at the time owing to construction work. Aftermath The Ente Nacional Regulador de la Electricidad will apply fines to the wholesaler energy distributor Transener. According to regulations, the maximum fine can be either 10% of the annual earnings or 50% of the monthly ones; Transener earned $9,838.5 million in 2018. Distributors Edenor and Edesur turned off 38% of the service, which harmed the situation as it was required a 52% to compensate the outage. Cammesa, the institution that