I'm very glad my children have been attending kindergartens and schools where scraped knees only get a band-aid. The oldest have been in two situations that could be described as "major":
1. She was three years old and in a fist figth with a two-year-old. In that figth, she fell and knocked in a few teeth (not out; they disappeared into the gums). The kindergarten called us, we took her to the dentist, and they gave us a form in case she would need dental work as an adult (some kind of insurance policy). They also got rid of the thing with sharp edges that she had knocked her teeth on. It took a while, but both her front teeth had to be pulled because they got infected. The permanent teeth are fine.
2. She was nine, and thought it was a good idea to hang upside down from the railings by the stairs, over the asphalt. It turned out it was a bad idea. Because she was dizzy and had neck pain, we were called and asked to take her to the doctor. Everything was fine, no concussion, but we got an insurance form just in case.
The only time we have gotten information from the school because someone else was injured, was one time a kid broke his leg skiing. They had to call in the ambulance helicopter, and the school thought we should get some facts, not just the tales from the kids.