Twiggy was at a newly opened small dog park when a group of other small dogs suddenly ganged up on her. Of course they couldn't catch her because she's a speed demon, but she must have caught her foot in a grate on the ground (extremely bad idea for a small dog park to have a grate on the ground) and broke her leg just above her ankle.
She's at the vet now and is doing fine. If you have a pet that you care for, I recommend getting pet insurance. I hear it's not too expensive and could save you a pretty dime in a situation like this. We were planning to purchase it but just hadn't gotten around to it. Now we have a significant vet bill to pay.
Hopefully we can pick her up today or tomorrow.