Twenty-five U.S. special forces killed early Saturday in Afghanistan were on a mission to rescue another team of military personnel pinned down by insurgents, a U.S. military official told CNN. The helicopter that went down in eastern Afghanistan carried 30 U.S. military members, including 22 Navy SEALs and three other special forces. They were part of a "quick reaction force" sent in to pick up others engaged in a fierce firefight, the official said. In the single deadliest incident since the start of the decade-long Afghan war, the Army Chinook carrying a team of U.S. special forces and U.S. and...