An American ship captain was freed unharmed Sunday in a US Navy operation that killed three of the four Somali pirates who had been holding him for days in a lifeboat off the coast of Africa, a senior US intelligence official said. One of the pirates was wounded and in custody after a swift firefight, the official said. Capt. Richard Phillips, 53, of Underhill, Vermont, was safely transported to a Navy warship nearby. The official was not authorized to discuss the matter publicly and spoke on condition of anonymity.