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. The failure came as a U.S. delegation visited Cuba Thursday and met with Cuban government officials.  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