A customer holds a candle as he gets his haircut at a barber's shop during a power-cut in Kolkata July 31, 2012. Grids supplying electricity to half of India's 1.2 billion people collapsed on Tuesday, trapping coal miners, stranding train travellers and plunging hospitals into darkness in the second major blackout in as many days. REUTERS/Rupak De Chowdhuri (INDIA - Tags: ENERGY SOCIETY TPX IMAGES OF THE DAY)