I sprained my ankle

In my volleyball class, I was practicing serves when I hit the ball real hard and it went flying... off course. The ball tore the wind and went zooming at a group of girls standing and chatting at the other corner of the field. I watched as it curves down at a very steep angle towards the middle of the crowd, trying to predict when and where it will land, hoping it wouldn't hit anyone. There was this girl bending down doing something, in a matter of a split second, my brain solved the equations for the ball's trajectory and ... no way. It really landed square on the back of her head, knocking her unconscious. People looked around to see what was going on, they had no idea since the ball went pretty high up.

I wasn't sure whether to be proud or embarrassed when I tried to apologize.