Electricity had returned to most of Italy by yesterday morning after a national blackout, although train services were disrupted overnight and authorities said power cuts could still hit about five percent of households.
Four deaths were unofficially attributed to the outage, the biggest in nearly a decade which struck at 3:20am on Sunday.
Almost all the country's 57 million people were affected, a scale similar to last month's collapse in the US Northeast and Canada. But coming on a weekend night its initial impact was less dramatic and caused less economic damage.
Authorities attributed the outage to a breakdown of electricity lines, some in heavy storms, from France and Switzerland -- neighbors supplying Italy some 17 percent of its power. But they disagreed on who was to blame.
Industry Minister Antonio Marzano called for an investigation, which highlighted Italy's heavy reliance on imported power.
The national grid, GRTN, blamed the blackout on problems in the Swiss and French networks.
"We will look at all the data in the computer," Marzano said at a news conference.
It was the fourth major Western blackout in two months, after cuts in North America, parts of London and Scandinavia.
The four deaths included a man killed in a traffic accident at an intersection where the lights had failed, an elderly woman burned by candles that fell on her, and two elderly women who fell down stairs.
About 110 trains were stranded when the power went out and hundreds of people were trapped in elevators across the country.
But the overall impact was muted, with most people asleep and emergency generators kicking in for hospitals and key services.
There was no estimate of losses, although retail trade association Confcommercio said the food industry alone lost about 120 million euros (US$138 million) of business and frozen food.
The blackout affected all of Italy except the island of Sardinia and some small pockets of the mainland, officials said.
The national grid operator said it was the biggest blackout since 1994 in Italy, which suffered several outages this summer.