Peter had spent a week visiting with his brother in Oklahoma. His sister-in-law and his 7-year old niece accompanied him to the airport for his flight back home. After verifying his seat number with the counter attendant, Peter came over to his relatives and stated that he'd have an additional three-hour wait. "How come?" his 7-year old niece asked. "My plane has been grounded," Peter explained. "Grounded?" she said "I didn't know planes had parents."