Spirit Airlines has apologized after it mistakenly put an unaccompanied child on the wrong flight during the holiday season travel rush.

The child was supposed to fly from Philadelphia International Airport to Southwest Florida International Airport in Fort Myers on Thursday. But the minor was “incorrectly boarded” on a flight to Orlando, according to the airline.

“The child was always under the care and supervision of a Spirit Team Member, and as soon as we discovered the error, we took immediate steps to communicate with the family and reconnect them,” Spirit said in a statement Saturday.

“We take the safety and responsibility of transporting all of our Guests seriously and are conducting an international investigation,” the airline added. “We apologize to the family for this experience.”

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Spirit did not provide any information about the child or explain how the mistake happened. WINK-TV, a television station in Fort Myers, identified the child as a 6-year-old boy and first-time flyer who was supposed to visit his grandmother.

“I ran inside the plane to the flight attendant and I asked her, ‘Where’s my grandson? He was handed over to you at Philadelphia?’ She said, ‘No, I had no kids with me,'” Maria Ramos, the boy’s grandma, told WINK-TV.

Fortunately, Ramos’ grandchild called her and said he had landed — 160 miles away. She told WINK-TV that she wants answers.

“I want them to call me [and] let me know how my grandson ended up in Orlando,” Ramos said. “How did that happen? Did they get him off the plane? The flight attendant – after mom handed him with paperwork – did she let him go by himself? He jumped in the wrong plane by himself?”