BUENOS AIRES, Argentina -- A blackout stripped electricity from tens of millions of people in at least three South American countries early Sunday in what the Argentine president called an "unprecedented" failure in the power grid.
All of mainland Argentina and Uruguay were affected, as was much of Paraguay. Utilities in Argentina and Uruguay reported failures in Brazil and Chile, but officials from those countries said they had not been affected.
Even at three countries, the blackout covered a region four times the size of Texas.
"This is the first time something like this has happened across the entire country," said Alejandra Martinez, a spokesman for Edesur, an electricity company in Argentina that serves parts of Buenos Aires and its suburbs.
Argentine authorities were working frantically to restore power. About 13 hours after the country went dark, power was restored to about 90 percent of its 44 million people, according to the national news agency Telam.
Argentine Energy Secretary Gustavo Lopetegui said crews were working to restore all electricity nationwide by this morning.
Power had been restored to most of Uruguay's 3 million people by midafternoon.
Paraguay lost power in rural communities in the south, near the border with Argentina and Uruguay. The country's National Energy Administration said service was restored by afternoon by redirecting energy from the Itaipu hydroelectric plant the country shares with neighboring Brazil.
Despite the restoration of power, the cause of the failure remained unclear.
"This is an unprecedented case that will be investigated thoroughly," Argentine President Mauricio Macri said on Twitter.
Uruguay's energy company UTE blamed a "flaw in the Argentine network" for cutting off power to all of Uruguay for hours. Paraguay's National Electricity Administration also said the breakdown began in Argentina's power network, which led to a fault at 7 a.m. local time that disconnected all generators at the Yacyreta hydroelectric dam from the regional grid.
Argentina's Edesur said on Twitter that the failure originated at an electricity transmission point between Yacyreta and the Salto Grande dam in the country's northeast.
Argentina has South America's second-largest economy, but its power grid is generally known for being in a state of disrepair, with substations and cables that were insufficiently upgraded as power rates remained largely frozen for years.
Lopetegui conceded that the blackout was "the type of failure that takes place regularly in Argentina and in other countries." However, he told reporters in Buenos Aires, "there was a chain of events that happened later that caused a total disconnection."
Although every possible cause for the collapse would be considered, "we do not believe that a cyberattack is within the possibilities," the energy secretary said.
The head of Transener, Argentina's largest power-transmission operator, agreed. A "technical issue" or simple humidity could have triggered the breakdown, Carlos Garcia Pereira said.
South Americans have considered the possibility of cyberattacks on electrical grids since Venezuela in March blamed a U.S. cyberattack for a severe blackout there. The United States denied responsibility, and leaders of Venezuela's electricity union have said the March blackout was most likely the result of a brush fire that destabilized the country's electrical grid.
Questions about the possibility of a cyberattack were raised because of the timing of the blackout: Argentina's gubernatorial elections were scheduled for Sunday.
The blackout delayed voting Sunday in Argentina's provinces of Santa Fe, Formosa, and San Luis. Voters marked ballots by candlelight or using their cellphones as flashlights under an "emergency protocol," newspaper Clarin reported.
Gubernatorial elections in Tierra del Fuego were unaffected. The province is the nation's southernmost, south of the Straits of Magellan, and it is not connected to the main power grid.
In Buenos Aires, a city of almost 15 million people, cars slowed to a crawl as traffic lights went dark, and trains and subways stopped on their tracks.
Businesses that were normally open on Sundays stayed shut, and public transportation was halted. Phone service was intermittent. Several panoramic photos shared on social media showed huge swaths of Buenos Aires with no lights on. Patients dependent on home medical equipment were urged to go to hospitals with generators.
Demian Luis Martinez, 36, a taxi driver, said he had spent the early part of his shift failing to find an open gas station. Everything was closed.
"It looked like a zombie city," he said. "There were car crashes everywhere."
Martinez said he had not seen any police officers directing traffic.
"The government is very lucky this happened in the morning and not in the middle of the night," he said.
Another taxi driver, Silvio Ubermann, said he'd never seen a blackout like Sunday's -- "never such a large blackout in the whole country."
Buenos Aires resident Maria Carrera said by phone around noon that she had to work Sunday.
"When I started my work, we didn't have any electricity in the building, the streets were empty, not a single business was open," she said.
Lucas Acosta, 24, also lives in Buenos Aires.
"I was just on my way to eat with a friend, but we had to cancel everything. There's no subway, nothing is working," he said. "What's worse, today is Father's Day. I've just talked to a neighbor and he told me his sons won't be able to meet him."
Alejandra Perez, 42, the caretaker of a 92-year-old woman, said she "started to frantically look for candles" when her building lost power. "I had to figure out how to get everything done without light."
Familiar with Buenos Aires' more common minor blackouts, she recalled that the water pumps in her building rely on electricity -- meaning that when the power goes out, the water sometimes runs short.
"I quickly got hold of any big pots and buckets I could find and filled them with water," she said. "We know exactly what to do."
The Argentine water company AySA asked customers to ration water Sunday because its distribution system had been shut down.
Many residents of Uruguay also said the size of the power failure was unprecedented.
"This is the biggest blackout in history, I don't remember anything like this in Uruguay," said Valentina Gimenez, a resident of the capital, Montevideo. She said early Sunday that her biggest concern was that electricity be restored in time to watch the national team play in the Copa America soccer tournament Sunday night.
Information for this article was contributed by Paul Byrne, Luis Andres Henao, Patricia Luna and Natalie Schachar of The Associated Press; by Amy Stillman, Jorgelina do Rosario, Fabiola Moura, Ken Parks and Patrick Gillespie of Bloomberg News; and by Daniel Politi and Clifford Krauss of The New York Times.
Technicians from an electric company in Buenos Aires, Argentina, work in the rain to fix a generator during Sunday’s blackout.
Cars move through an unlit street Sunday in Buenos Aires. Traffic in the city slowed to a crawl because of the blackout, and trains and subways stopped on their tracks.
A Section on 06/17/2019
Print Headline: Blackout hits three nations