Argentina's state news agency says that most of the nation's grid is back up and running after a massive blackout that left tens of millions of people without electricity.
Telam said Sunday that Argentina had restored power to 90 percent of the South American country. Power also has been restored to most of Uruguay's 3 million people.
The massive blackout had hit Argentina, Uruguay and Paraguay on Sunday in what the Argentine president called an "unprecedented" failure in the countries' power grid.
Authorities were working frantically to restore power, but 12 hours after the country went dark, more than a quarter of Argentina's 44 million people had still been without power and the cause of the outage remained unclear.
The president of the Center for the Study of Energy Regulatory Activity in Argentina says that a massive blackout that left millions without electricity "has never happened" in the country.
Raúl Bertero is a professor at the University of Buenos Aires. He said Sunday that systemic operational and design errors played a role in the power grid's collapse.
"A localized failure like the one that occurred should be isolated by the same system," he said. "The problem is known and there is technology and studies that (work to) avoid it."
He also said that independent experts should be asked to determine what happened.
The failure left many in Argentina, Uruguay and Paraguay without electricity for hours.
Argentina's energy secretary says that the cause of a massive blackout is still unknown.
Gustavo Lopetegui said at a press conference Sunday: "We don't have information about why it occurred."
The secretary also said that electricity is expected to be 100% restored by the end of the day.
Argentine energy company Edesur said that a failure in the Argentine interconnection system originated at an electricity transmission point between the power stations of Yacyretá and Salto Grande in the northeastern part of the country.
Argentine energy company Edesur says that electricity has been restored to more than 1.5 million people.
President Mauricio Macri also said that 50% of the country had power after a massive failure in Argentina and Uruguay on Sunday morning left many in the dark.
Macri said on Twitter: "As time passes, service will be restored for all customers."
The cause of the blackout was not immediately clear.
Edesur said that a failure in the Argentine interconnection system originated at an electricity transmission point between the power stations of Yacyretá and Salto Grande in the northeastern part of the country.
Uruguayan energy company UTE said 75% of service had been restored in its country.
A massive blackout left millions without electricity in Argentina and Uruguay on Sunday after an unexplained failure in the neighboring countries' interconnected power grid. Authorities were working frantically to restore power but only about a half a million in Argentina had electricity back by early afternoon.
Voters cast ballots by the light of cell phones in gubernatorial elections in Argentina. Public transportation halted, shops closed and patients dependent on home medical equipment were urged to go to hospitals with generators.
"I was just on my way to eat with a friend, but we had to cancel everything. There's no subway, nothing is working," said Lucas Acosta, a 24-year-old Buenos Aires resident.
In Uruguay, power was being more steadily restored, with lights back on in at least three regions by early afternoon.
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