My son fell off the monkey bars!?

and landed on the brick below, he and and the teacher confirmed she seen it, he landed on his wrist (fractured) and he says he hit his head too. No one called but they kept asking him if he was okay, and how was his wrist... he said he was ok. but when he got off the bus, his wrist was swollen, and loaded up my girls and headed to the sitter and an er. He wouldn't move his arm much, didn't cry. but i heard the school should pay the hospital bill... is this true? i live in Indiana, help?