Argentine President Mauricio Macri on Sunday vowed to fully investigate the massive electrical failure that plunged Argentina and Uruguay into darkness. Both countries share an electrical grid, and when the electricity was cut off, tens of millions of people were without power. The lights went out on Sunday morning, and by Sunday evening, officials said more than 80 percent of customers in Argentina and 88 percent in Uruguay had electricity again. Gustavo Lopetegui, Argentina's energy minister, said the electrical system is "robust," and while "we're not ruling out any possibility ... we don't think it is down to a cyber attack." Argentine media reports that officials are linking the outage to a failure in the transmission of electricity from a hydroelectric dam.

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