The authorities had to search a plane at LaGuardia Airport after a bomb threat was reported.
The Port Authority, which runs the airport, said American Airlines Flight 382 from Chicago landed safely and 117 passengers and five crew members were taken off the plane before the search began.
Bomb-sniffing dogs were used for a security sweep, and luggage was being matched to passengers as it was removed from the plane.
The discovery of the submarine has unveiled a few "inconsistencies." For example, how can one explain the fact that the sub was found where it needed to be searched for from the start?