Flight data recorders revealed a loud sound and then all recording ceased. No evidence of a bomb has been found on recovered wreckage. Front cargo door found in pieces. The aircraft was a Boeing 747-131, an early 747 with high flight time and flight cycles. Boeing 747-131 series high flight time aircraft are prone to cargo door malfunctions.
Doors pop open in climb or just after.
Door popping open exposes large hole in side of nose. Large hole in side of nose can tear nose off when subjected to high air pressure loads. Nose tearing off leaves rest of plane to crash resulting in two wreckage trails. Nose tearing off is sudden and total and leaves no time for calls to ground from crew or for recorder data to continue. Door opening and tearing off would be visible as streak as it reflects evening sun at 13500 feet near New York City on July 17th.