On 16 June 2019, a large-scale power outage struck most of Argentina, all of Uruguay, and parts of Paraguay, leaving an estimated total of 48 million people without electrical supply. By the following day it was confirmed that power had been restored to most of Argentina and Uruguay, and Argentine President Mauricio Macri promised a full investigation. The blackout is believed to have been caused by an operational misbehavior from Transener, a transmission lines operator in Argentina. A 500 kV line running from Colonia Elía to Campana, crossing the Paraná Guazú river, was down on undergoing maintenance to repair the tower number 412, whose base had been suffering from erosion by the river. The company made a bypass for this tasks, using a nearby overhead line, but missed to reflect that network grid change in the Automatic Generation Shutdown system (in spanish: DAG), which is designed to alert energy generators of network changes that would require a lower of energy generation. This caused, after a short circuit which lowered demand, an excess of power generation in the grid, a lack of synchronization of power plants, loss of balance, and a low frequency in the network. In about 30 seconds, a succession of automatic disconnections from the grid caused a blackout that came to affect 50 million users in the continent. Timeline At 7:07 a.m. (UTC-3) on 16 June 2019, Argentina's power grid "collapsed", according to Gustavo Lopetegui, the country's Energy Secretary. The failure occurred in the Argentine Interconnection System. In total, an estimated 48 million people lost power. The blackout affected most of Argentina (Tierra del Fuego in the country's far south was not affected) and Uruguay, along with parts of Paraguay. Although some media reported blackouts in parts of Chile and parts of southern Brazil, this claim was denied by the Chilean and Brazilian national authorities. Macri called it "unprecedented". Argentine distributor of electricity Edesur announced on Twitter at 7:50 a.m. that all of Argentina and Uruguay had lost power as a result of the incident. It caused disruptions in subways and trains, but did not affect electric and non-electric airborne transport. According to Edesur, power had already been restored to some parts of Buenos Aires by 10 a.m.; Edesur reported that it might take many hours to restore power to all affected customers. By 1:30 p.m. power had been restored across 75% of Uruguay. By mid-afternoon 50,000 people