U.S. warships and helicopters stalked a lifeboat holding an American sea captain and his four Somali captors Sunday as Somalis reported negotiations for his release have collapsed and his crew briefed FBI agents about how they fought off the pirates who boarded their ship, AP reported. A Somali man involved in the negotiations and another in telephone contact with the pirates said clan elders have been trying to negotiate a free passage for the pirates in exchange for the release of Capt. Richard Phillips, but the talks broke down Saturday night over the U.S. insistence that the pirates must be arrested and brought to justice. Nineteen American sailors guarded by U.S. Navy Seals reached safe harbor in Kenya's northeast port of Mombasa on Saturday night, exhilarated by freedom but mourning the absence of Capt. Richard Phillips, who sacrificed himself as a hostage to save them.