Home Alone is one of those movies that presents a conflict that would be so easily resolved in the real world. In the world of Kevin McCallister, however, people don't pick up the phone and the McCallisters apparently have NO ONE who can check on them. Writer John Hughes does a pretty good job, however, of making sure all easy resolutions are ruled out. Here's a breakdown of how Kevin gets stuck "home alone."
The McCallisters are traveling to Paris tomorrow. Kevin's aunt, uncle, and cousin Fuller are joining them, so extra beds are needed. Kevin is asked to sleep with Fuller in the attic.
Kevin is asked to pack his suitcase and presumably does not do so because he doesn't know how.
After Kevin shoves his older brother, Buzz, Kevin's dad cleans up the mess he's made, accidentally throwing out Kevin's plane ticket.
Kevin is punished and sent to bed in the attic. Fuller won't join Kevin, leaving Kevin alone for the night.
During the night, heavy winds cause a branch to break, taking down a power line with it, cutting power to the house.
As a result of the power outage, the alarm clocks do not go off in the morning and the McAllisters are completely crazed in an attempt to make their flight.
In the head count, the nosy kid across the street is mistaken for Kevin, so it appears everyone is accounted for.
The phones are of course out and cannot be repaired for several days.
The McCallisters just make their flight. The gate attendant tells the group to take whatever seats are left in coach.
The grown-ups are in first class, so they're not monitoring the kids.
Kevin actually believes he has magically made his family disappear, so he has no cause to seek help.
Failed contact attempt #1: The captain gets someone on the ground to call the McCallister home. The phones are still out.
Failed contact attempt #2: Having landed in France, Kevin's mom instructs some of the kids to call everyone they know. They can't get ahold of anyone.
Failed contact attempt #3: They try to contact a neighbor, but no one picks up.
In fact...somehow ALL the neighbors have left for the holidays.
Failed contact attempt #4: Kevin's mom gets through to the police, who agree to dispatch an officer over to the house...
However, Kevin doesn't answer the door when the policeman knocks. Kevin has just seen the robbers and is terrified.
Next, all the flights are booked for the next two days.
Failed contact attempt #5: Once in Paris, Kevin's dad makes more calls, and still comes up with nothing.
Further complications come from operators who are speaking in a foreign language. It's unclear who he's talking about — "they're all shopping" — could be co-workers who left work early to do holiday shopping.