At the largest terminal at New York’s John F. Kennedy International Airport on one of the busiest travel days of the year, security lapses enabled an unticketed passenger to board a plane to Paris in a shocking breach that one aviation expert said should serve as a “wake-up call” for the airline industry.

New details on how a woman managed to sneak onto a Delta flight from New York to Paris have raised serious questions about security during the busy holiday travel season.

It remains unclear how the person managed to bypass security at JFK Airport and board the Delta Airlines flight to Paris.