People look at a barricade set up by residents protesting against prolonged power outages in Havana, Cuba, Wednesday. Ramon Espinosa/AP hide caption toggle caption Ramon Espinosa/AP HAVANA — Cuba's national energy grid suffered a major failure early Thursday that severed power to the island's eastern provinces, authorities said, as residents in the capital Havana faced ongoing blackouts. Cuba's aging power grid has eroded in recent years as it faces a prolonged economic crisis, recently made worse by a U.S. energy blockade of the island, where daily life can be an ordeal for many of the country's 10 million people. The state-run Electric Union said the collapse had stripped power from all eastern provinces from Guantánamo to Ciego de Ávila, and that crews were working to restore power, but it did not give an estimate for how long it would take.…