There was no distress call, no indication of enemy depth charges exploding or bulkheads breached, just a dead silence that stretched from a few days into 60 years. The USS Grunion disappeared in July 1942, leaving 70 American families grieving and the three sons of skipper Mannert L. "Jim" Abele without a father. Abele's boys -- who were 5, 9 and 12 and lived in Newton, Mass., when their father disappeared -- grew up and built their own lives. But they dwelt on the fate of their father. At 2 a.m. Wednesday, a grainy sonar picture e-mailed via satellite appeared...