Brazil vows to find cause of huge blackout

Brazil's government vowed Wednesday to find what caused a massive and mysterious blackout that plunged half the country into the dark and raised questions over its preparedness to host the 2016 Olympics.

President Luiz Inacio Lula da Silva dismissed doubts over Brazil's energy generation, saying there was no shortfall, but admitted the cause of the four-hour outage late Tuesday into early Wednesday was unknown.

"There was no lack of energy production. Energy continues to be produced. We had a problem in the transmission line, and we still haven't detected the problem," he told a media conference in Brasilia with visiting Israeli President Shimon Peres.

The outage, which hit at 10:15 pm Tuesday 0015 GMT Wednesday, left an estimated 70 million people without electricity, especially in the major southern cities including Sao Paulo and Rio de Janeiro.

Related article: World's worst power cuts. Thousands of people were trapped in immobile elevators and subway trains. Cars were forced to nose through intersections made dangerous by suddenly extinguished traffic lights. Off-duty police were called up out of widespread fears of a nocturnal crime wave.

Blame for the emergency was leveled at Brazil's biggest power plant, the Itaipu hydroelectric station that straddles the border with Paraguay and supplies both countries with much of their energy needs.

But while officials said the plant's 14,000 megawatts suddenly disappeared from the national grid, they were at a loss to explain why, exactly.

"National interlinked grid is operating normally and no damage has been identified in its circuits and transmission towers," said a statement by Furnas, Brazil's state-owned electricity company responsible for the affected area.

It said the search was ongoing for the cause of the blackout and cautioned "any diagnostic at this time is purely speculative."

The state electricity company of Paraguay, which also suffered a 30-minute blackout across its entire small territory during the emergency, said the problem was not with Itaipu but with transmission lines feeding energy from the plant.

"It happened as a consequence of a failure of three high-tension transmission lines of 750,000 volts each in the Sao Paulo region," a spokesman for the ANDE company, Jacinto Bernal, told AFP.

He said suggestions advanced by Brazilian Energy Minister Edson Lobao and other Brazilian officials that a fierce storm somehow disrupted Itaipu's output were wrong.

"They should drop the pretext of attributing the problem to bad weather," he said. "Itaipu was able to keep producing but wasn't on-line."

Itaipu supplies 20 percent of the energy needs of Brazil, Latin America's most economically active nation, and 70 percent of Paraguay's. All of that and more dropped out of the grid. It was the first time the plant went off-line since it opened in 1982.

The blackout occurred two nights after the US television network CBS broadcast a report in which unidentified former US national security officials claimed massive power outages in Brazil in 2005 and 2007 were caused by cyber hackers attacking control systems.

Although Brazilian media were skeptical of that assessment, the US channel said those incidents should serve as a wake-up call to the United States, which could see its own power supplies hit by computer sabotage.

Brazil's energy ministry was to hold an urgent meeting later Wednesday with all the country's grid operators to determine the exact causes of the outage and what can be down to prevent a repetition.

The city, which is already struggling with rampant crime, was the most affected by the power cut, according to electricity grid officials.