Power was restored in Cuba early Monday after a massive outage caused by a malfunction in a high voltage power line cast much of the country into darkness for hours.
"I hope it is not the beginning of another energy crisis. I get chills just thinking about it" said carpenter Ricardo Aldana, 48.
The blackout, which began at 10:08 pm local time (0008 GMT Monday), hit 10 of Cuba's 15 provinces, including Havana. Six provinces went totally dark for three hours, the state-run Electric Union company said.
A malfunction on a high-voltage line between the the cities of Ciego de Avila and Santa Clara disrupted service from the eastern province of Camaguey to Pinar del Rio at the western end of Cuba.
Residents said Pinar del Rio, Artemisa, Havana, Mayabeque, Matanzas and Cienfuegos were left completely without electricity.
The cause of the malfunction was under investigation, the company said.
The situation in the capital -- where more than two million of Cuba's 11 million people reside -- remained calm, although the police presence on some streets had been noticeably beefed up.
Many people in Havana left their homes to spend the night in the open because they could not use fans or air conditioning, and the heat inside -- about 30 degrees Celsius (near 90 degrees F) -- quickly became unbearable.
After three hours, electricity began to return to some areas of Havana but others remained in the dark.
"The heat is unbearable. There is no way to sleep," complained Xiomara Castellanos, 76, out past midnight in the Vedado district of Havana.
A young woman talking about being unable to sleep drew an offer of "Come home, sleep at my house," in a country where laughing at crises is a national pastime.
Others fretted about losing the food they had in refrigerators, no small loss for Cubans whose average salary is less than $20 a month.
In Cienfuegos, the blackout lasted about an hour, residents said.
While rolling blackouts to save energy are not unusual in cash-strapped Cuba, a broad failure of the power grid like this is rare.
Energy shortages are the Achilles heel of Communist-run Cuba's economy, which for more than a decade has been propped up by subsidized oil from ally Venezuela.
Throughout the blackout, Cubans searched the radio dial for information about the blackout; state broadcasters kept broadcasting as if the worst blackout in years had not taken place hours after it began. Hours later the power company started offering details.
In the 1990s "Special Period" of acute economic distress in Cuba, following the collapse of the Soviet Union and its other allies, power rationing was the norm. And in 2004 a breakdown at Cuba's main power plant led to daily blackouts of 12 to 15 hours.
Still, pro-government blogger Yohandry saw a victory in the rough night, saying: "Such a big breakdown, half of Cuba in the dark, and Cuba restores power in six hours, without crime, without violence, without deaths."