They estimated the ball was travelling 120 mph when it hit a young girl in the head. They've released more information on her condition. Here are the details. 

The little girl was carried out of Yankee Stadium after being knocked out by the ball. I am sick to my stomach watching this video. You don't actually see her get hit, or the aftermath (the announcers call it graphic), but just watching the players' reaction and all those in the stands, you know it's really bad.

Even as a softball player with many, many years of experience on the field, I don't think I would have seen that ball coming. It has been a constant battle to get the safety net extended at all fields. The Yankee Stadium does not have the extended net.

In an interview with Yahoo Sports, Minnesota Twins second baseman Brian Dozier said “every stadium needs to have nets. That’s it. I don’t care about the damn view of the fan. It’s all about safety. I still have a knot in my stomach. I hope that kid’s OK. We need nets. Or don’t put kids down there.”

The Yankees told ABC News that the girl was taken to a hospital for treatment, and New York manager Joe Girardi said he had been told by team security that she was OK.