I didn't have a grandchild mishap, but once I layed a 100 block quilt out on the living room floor so I could go upstairs and look over the balcony to see if everything was in place. Everything was fine, but noticed that I needed to get to my son's basketball game. Well when I arrived back home not a block was laying in place as my two cats had a wonderful time running through the blocks and I imagine throwing them in the air. Lesson learned. Take the time to stack them and carry them to the sewing room. I still chuckle to myself thinking of the fun they must have had. :D