I am also curious. When you broke that bone, did the school take you to hospital right away or did they wait for your parents/guardian to arrive because they are not allowed to take kids to hospital. I am asking because if something like this happens today, they will most likely wait for at least one parent/guardian to arrive.
I predict you don't have kids and don't hang with parents. Thru the grapevine, social media, and from the other kids you hear some scary stories, like it or not.
If its serious they call an ambulance or they get sued into oblivion, therefore they call an ambulance for anything more serious than sniffles, and the hospital is legally required to stabilize the condition of anyone who comes in (see emergency room full of illegals, etc). So if your kid has a fever seizure at day care or takes a very serious fall at recess or gets knocked out in gym, you'll get contacted by the hospital while your kids already being treated.
Also if you have kids you know all about filling out multi page contact sheets for pretty much any facility that has your kids, from day care to after school basketball. They'll track down an adult via landlines, employer name, relatives, friends parents... its all business as usual.
I can assure you that at least away from the coasts no one leaves a not-breathing kid laying in a pool of blood until the parents arrive, etc.
My kid would be taken to the hospital right away. I know because it has happened to her classmates. The school even has my waiver signed allowing them to do this in case of emergency as defined by the school nurse.