Thirty U.S. troops, including 22 Navy SEALs who were killed when their helicopter was shot down Saturday in Wardak province in Afghanistan, were on a mission to go after a Taliban leader responsible for attacks against American troops. Two U.S. military officials told CNN that the SEALs, most of them part of SEAL Team Six, were called in to assist another unit on the ground pinned down in a firefight. Eight other Afghan troops were killed in the crash. NATO is investigating the tragedy.
