A Green Beret is one of two Americans killed in Afghanistan , a U.S. official says . Newly installed U.S. Defense Secretary Chuck Hagel visited Afghanistan this weekend on his first overseas trip since his confirmation . The other was Staff Sgt. The assailant is dead , a U.S. official says . It was first fatal `` green-on-blue '' attack on coalition troops in two months .
A Green Beret is one of two Americans killed in Afghanistan , a U.S. official says . The other was Staff Sgt. The assailant is dead , a U.S. official says . It was first fatal `` green-on-blue '' attack on coalition troops in two months .