Jim Hurd II crouched among the petunias and wispy pennisetum grasses at the TWA Flight 800 memorial Monday, trying to fix broken lights for Tuesday night's prayer service. Since his son, Jamie Hurd III, died on the flight on July 17, 1996, Hurd, 62, travels to Smith Point Beach each July on the anniversary of the crash from his home in Severn, Md. During much of the rest of the year, he urges airline industry groups to outfit airplanes with a device that would have prevented the explosion that killed his son. Yet 11 years after the center fuel tank...