Blackout in South America raises questions about power grid

The huge blackout that left tens of millions of people in the dark in Argentina, Uruguay and Paraguay over the weekend raised serious questions about the vulnerability of the power grid in South America and brought criticism down on Argentina's leader.President Mauricio Macri promised a thorough investigation into the cause of what he called an unprecedented outage.Energy officials said the findings would not be available for 10 to 15 days, and they had no immediate estimate of the economic dama