When Delta Flight 1880 landed late Saturday at Logan International Airport in Boston, the pilot went on the intercom to make a request of the passengers preparing to grab their carry-on bags: Sit for a moment and honor a fallen soldier. "The pilot said, 'We have a hero on this flight and sadly, he isn't with us, but his mother is escorting his remains,' " said Barbara Bell, sister of Sgt. Pierre A. Raymond, 28, an Army reservist from Lawrence, Mass., who died Tuesday in Germany after being wounded in Iraq. The normal bustle of an emptying airplane immediately ceased,...