A trip to the store and a tipped shopping cart

I thought I was going to make a quick trip to Office Depot to get 2 things, Binders for Tyler's homeschooling and Boxes to do some more packing around the house. So I get there, and the binders were full price, I love picking these up when they have them on sale and they were out of the 10 pack boxes. I ask for help and so as the sales associate is searching the shelves for boxes Tyler decides he will finally climb back out of the shopping cart, I told him when he got in he needed to sit still, but of course that doesn't happen, instead him and his sister are bickering over who is squishing who, etc. I told him to get out. Well kids know when you are preoccupied because while I'm talking with the sales associate they TIP THE CART onto it's side. (this was the 2nd time he has tipped her cart, last time it was one of those little tiny carts and only she was in it and when it tipped she landed on him as he landed on the floor) I managed to break there fall but Megan's head still hit the floor so hard and it was so loud. Between the weight of the cart and the kids I could not catch it even though I was standing right there. It even broke the wheel on the bottom of the cart and my fingernail. When they do something they do it right. I was so upset with him for not listening. He tried climbing OVER his sister to get out...... I thought for sure social services would be knocking on my door by the time I got home. Thank goodness the store associate was sooo nice about every thing. He even went and got me a new shopping cart while I tended to Megan who was screaming. Thank goodness also they were both ok. I never would have imagined my child would have tipped a cart once much less twice. I so hope that it will never happen again. GOD was keeping his eye on us again today, for he knows that I am not perfect.