In the 1990 Christmas movie Home Alone, the McCallister family experiences a nighttime power outage. As a result, their alarm clocks don't go off and the family wakes up only when the airport shuttle van arrives to pick them up. This electrical problem is central to the plot. If the McCallisters are not frantically rushed to leave, it's very improbable that Kevin would have been left home alone.
How likely is it that there would be a power outage on that particular night? Physicist Luís Batalha produced this brief analysis on the subject. His conclusion is that the likelihood of this event is about 0.13%.
Kevin got lucky.