Their 2,300 names known only to family and close friends, the U.S. Navy SEALs are a tight brotherhood who carry out some of America's riskiest missions, including, in May, the assassination of Osama bin Laden. When a member is slain, fellow SEALs gather at graveside in uniforms without name tags, as if about to embark on a mission. One by one, they remove the SEAL Trident pins from their chests, then pound the tridents into the wood coffin with their bare fists. Sadly, that rhythmic pounding will be repeated in the weeks to come. On Aug. 6, 22 SEALs, along with eight Army and Air Force troops, seven Afghan commandos and a civilian interpreter, slipped into the Tangi Valley to strike a Taliban compound. As they hovered, a rocket-propelled grenade struck their helicopter, killing all onboard. The attack reportedly took a harsh toll on Seal Team 6, the unit of roughly 250 members that included those who killed bin Laden (though none were onboard). As word spread, the pain was acute. "My heart is breaking. I know what is going on in those families," says Amy Looney, whose husband, Brendan, was a SEAL killed in action in 2010. "They will be embraced and held forever by the SEAL community."