Number of kids flying alone soars: so do airline surcharges

Three kids spend $700 in babysitting money to board a Southwest Airlines flight from Jacksonville, Fla. to Nashville, Tenn. alone with nary a soul asking them for identification, where they're headed, or why they're by themselves.

A 9-year-old Canadian boy is stranded for eight hours at Chicago's O'Hare International Airport after a United Airlines employee forgets to retrieve him from a kids' lounge in time for his connecting flight.

Delta Airlines mixes up two kids' itineraries -- sending a boy who was supposed to go to Boston to Cleveland and a Cleveland-bound girl to the Massachusetts capital instead.

These are all recent examples of unintended consequences for kids flying by themselves -- the one in Nashville just last week. And they underscore the fact that more youngsters than ever are alone in the air, putting greater responsibility on airlines to keep track of them.