Walking up to the edge of the Grand Canyon that July day was as suspenseful as creeping downstairs on Christmas morning. Our group of nine children and their grandparents all obeyed the tour guide: "Walk looking down. And don't look up till I say so." But when the guide said, "Now!" my husband, Dave, and I were more focused on Ben, our 12-year-old grandson, than on the magnificent canyon suddenly spread out before us.