和我同龄的弟弟咋玩捉迷藏的时候发生了意外事故，因为什么呢?

So, a funny story then, about my brother. First of all, he's my twin brother, so he's the same age as me, 26, and when we were, I think, 8 years old, it was during the summer. It was a very, very hot day, so all the windows in the house were open, and we decided to play hide and seek, so my brother, Daniel, he goes upstairs and he sits by the window, on the window ledge, and he's waiting for us to come and find him, so he leans back, but not realizing the window's open he falls out of the window, so he falls about 15 feet and he break both of his arms and all we hear is this screaming and we think, ah you know, he's just kidding around and them my mom goes out and sees that he's lying on the floor, one bone sticking out of one arm, the other one's all twisted, so we call the ambulance and everyone's crying. My mom is being sick with the shock, and he goes to hospital. We were really, really worried, you know, is he going to die, or whatever, and he was fine. He broke both his arms but he was in hospital for about two weeks I think. Yeah, it was really nasty. He's got a horrible scar now.