Gas Tanks

This past weekend, I made a trip to Lowes in order to exchange my bbq's propane tank.  They have a cool program (like most big box hardware stores do) where you can exchange empty tanks for full tanks.  While I waited for the clerk to unlock the cage and exchange my tank, a man arrived to the front of the store to load up propane tanks into his truck.  He had purchased 3 empty ones of his own.  As I watched him drive away, I chuckled remembering a time my dad had done something similar.
My dad loved to grill on the bbq.  He cooked a lot of our family meals and many of them were made on the grill.  When my parents moved from California to Hawaii he bought a new grill for the backyard.  Shortly after, their local Costco had empty propane tanks on sale.  As an avid griller, he wanted a few on hand.  On a side note, this was a common theme with my dad.  Why have one extra when you can have 3 extra because you bought them inexpensively at Costco? Now the Costco in Kona happens to be on the way to the Kona airport from my parents' house, and during that sale I was was flying into Kona for a visit.  They decided to make a stop at Costco before coming to pick me up at the airport.  That was a logical plan in order to not make the trip two times, however it wasn't all that smart of plan.  You see, 9/11 had happened less than two years before and the airports, even the teeny island ones, were on high alert.  The Kona airport had police at their one and only entrance in order to check ALL cars that came into the airport.  My parents had driven their Jeep Cherokee that day to accommodate three propane gas tanks AND my luggage.  As you can imagine, the police were not thrilled to see those gas tanks.
My parents explained the tanks and after demonstrating they were empty, the police let my mom meet me at baggage and sent my dad and the car off into parking lot exile.  When I got off the plane and said my hellos to my mom, I asked where my dad was.  She explained their mistake and detainment as we walked across the airport to where my dad was waiting with his propane tanks.