We were late heading to my son's birthday party in SLC, so we hurriedly stopped to buy a gift card and a very large helium-filled mylar balloon at the local market. At the top of the highest mountain pass in route, the balloon exploded, scaring the badookie out of us before we realized what had happened. Balloon purchased at 5500' and exploded at 8500' elevation. Afterwards, my wife was thinking "we've got to find another balloon". I was thinking "number one rule, don't hold your breath while scuba diving". Anyone living in the mountain states of the American west sees every day the potato chip bags on store shelves blown up like a TSA officer stuffed into a cop suit with the buttons screaming for mercy.