I Broke My Sister's Prize Doll

My sister won a beautiful doll at the state fair last year. It was her prized possession, and she took great care to keep it in its box on the top shelf of her closet. But when we were playing hide-and-seek yesterday, I accidentally knocked over my ladder, which crashed into the box where the doll was stored. I didn't tell anyone because I thought they would be upset with me for being so careless. Now every time I see that empty space in her room, I feel awful.