"Zeroing In on Mystery of an Old Site Called Hades"
"WASHINGTON, DC -- For decades, affluent families have flocked to Spring Valley, a quiet neighborhood hugging the northwestern boundary of the nation’s capital. True to its name, magnolias are blooming and daffodils carpet the yards. But during World War I, soldiers called it Death Valley. It was here that the Army cooked up chemical weapons, launched poison-packed mortar shells and sent gas clouds billowing over the fields."