In a story reminiscent of the film “Catch Me If You Can,” investigators are trying to figure out how an unnamed 9-year-old boy slipped through three levels of security at Minneapolis-Saint Paul International Airport Thursday and boarded a Delta flight to Las Vegas -- all without a ticket.

“The fact that the child’s actions weren’t detected until he was in flight is concerning,” said Patrick Hogan, spokesman for Metropolitan Airports Commission, which runs the Twin Cities’ airport. “More than 33 million people travel through Minneapolis-Saint Paul International Airport every year, and I don’t know of any other instance in my 13 years at the airport in which anything similar has happened.”

Hogan said the unattended lad from Minneapolis arrived at the airport last Thursday by light rail transit, and was screened by Transportation Security Administration officials at security Checkpoint 4 in Terminal 1-Lindbergh at 10:37 a.m. CDT. After screening, the child then proceeded to Concourse G, where he boarded Delta Air Lines Flight 1651 to Las Vegas for an 11:15 a.m. departure. The flight was not fully booked and had several open seats available.

All children between the ages of five and 14 must be signed up for Delta’s Unaccompanied Minor Program when not traveling in the same compartment with their parent or legal guardian or an adult who is at least 18 years old. It was when Delta flight attendants realized that the child was not listed as part of this program that they alerted authorities.

“The flight crew became suspicious of the child’s circumstances in flight and contacted Las Vegas Metropolitan Police, who took the child into custody upon landing and transferred him to Child Protection Services,” Hogan noted, adding: “Fortunately, the flight crew took appropriate actions to ensure the child’s safety.”

Airport police reported the incident to the TSA, Delta Corporate Security, the Minneapolis Police Department and the Hennepin County Attorney’s Office. The TSA said in a statement Sunday that it was cooperating with the agencies involved and would review whether it needed to change its checkpoint procedures in light of Thursday’s incident.

A TSA spokesperson told CBS Minnesota Sunday that staffing at the airport was low due to the number of employees furloughed in the wake of the federal government shutdown. The agency later clarified that all front-line officers are working through the shutdown, adding, “The child was screened along with all other passengers to ensure that he was not a threat to the aircraft.”

According to surveillance footage, the precocious 9-year-old first traveled to the airport last Wednesday to scope out the scene. He removed a bag from the carousel, went through TSA security and had lunch at a restaurant in the area that leads to the concourses. He ditched the bag and the bill and did not return until the next day. Hogan said officials returned the bag to its rightful owner with all items accounted for.

Security footage from Thursday, meanwhile, revealed that the boy successfully embedded himself in with another traveling family to avoid suspicion. The video also showed that he spoke with a Delta agent at the gate before rushing down the jetway and onto the plane while the agent was busy with other customers.

A Las Vegas Metropolitan policeman was quoted as saying that the boy was “more worldly than most 9-year-old kids,” but he is not the first child to evade airport security in recent years. Just before the London Olympics in 2012, 11-year-old Liam Corcoran made it all the way from Manchester, England, to Rome on at flight with no ticket, passport or guardian. Like the Minneapolis stowaway, authorities believe Liam passed through both border control and ticket checks by closely tailing other families.