Sao Paulo Brazil

• Blackout causes panic in Rio and Sao Paulo• One third of population plunged into darknessIt was a typical Tuesday night in South America's largest nation. In Sao Paulo, maids and security guards made their way home after another day's grind. In Rio, samba musicians began taking to the stage, their faces glazed in sweat from the tropical heat. And in one of Ipanema's most exclusive seafood restaurants, Madonna prepared for a romantic dinner...