Good thing it was a baby tooth!
I was in the house at the time playing with Falyn when Kayli runs in crying. She is holding her head and blood is coming out her mouth. Talia was outside with her, but was reading and facing the other direction. She said that Kayli was swinging and then she heard a big thump.
Kayli finally calms down long enough to tell use she fell out of the swing and hit the back of her head. When she hit her head, her top tooth bumped into the already loose bottom tooth and making it so loose that it just fell out when you touched it.
You can see in this picture where the tooth was that fell out.