Port Authority said it happened at Terminal B around 10:20 a.m.
The Spirit plane was parked near the gate and was going through de-icing when the incident occurred, according to the airline and there were no injuries.
Passengers deplaned normally and Spirit said it's working to get passengers to their destinations as soon as possible. The airline also took the plane out of service for evaluation by its maintenance team.
The Singapore plane was about to take off for the world's longest flight, which is more than 19 hours.
This incident occurred in an area where air traffic controllers do not manage aircraft, per the FAA.
Singapore Airlines did not immediately respond to a request for comment.
The FAA will investigate.
(ABC News contributed to this report.)
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