After hundreds of e-mails and brief calls home once a week from his base in Kuwait, the 54-year-old master gunnery sergeant eagerly awaited this past Friday night, when he would finally see his wife and two daughters. With balloons, posters, and his "Marine Corps green" Toyota Tundra in the parking lot at Manchester Airport, they bearhugged him as soon as he stepped off the plane. Three hours later at their home in Weare, N.H., his daughters said prayers thanking God that their father returned safely. His wife was getting ready for bed. And then she heard him collapse on his...