An Indian commuter walks past the status board for trains displaying "Indefinite Late" for all the trains following the power outage that struck in the early hours of Monday, July 30, 2012, at a train station in New Delhi, India. Northern India was plunged into darkness Monday after a supply grid tripped because of overloading, officials said. (AP Photo/Altaf Qadri)
Half of India's 1.2 billion people were without power on July 31 as the grids covering a dozen states broke down. More than 600 million people were left without power in one of the world's biggest-ever blackouts.