A top Brazilian official says blackouts that darkened Brazil's two largest cities and other areas were caused by the failure of a hydroelectric dam that supplies the nation with 20 percent of its electricity.
Mines and Energy Minister Edison Lobao says authorities do not know why the dam went offline. He says a possible cause was a large storm that hit the area around the dam straddling the Brazil-Paraguay border.
Lobao said Tuesday night that Brazil lost 17,000 megawatts of power. Rio de Janeiro and Sao Paulo were among the hardest hit cities.
The blackouts came three days after CBS's "60 Minutes" news program reported that several past Brazilian power outages were caused by hackers. Brazilian officials had played down the report before the latest outages.
I strongly recommend going to the "60 Minutes" website and watching the segment. (I tried to embed it on the blog but failed.) It's called "Sabotaging The System."