This all happened in the state of TX.
My 20 year old son was at a party. I am not sure exactly what happened, but my son ended up getting attacked by his now ex-friend (lets refer to this ex-friend as Mark), Mark's father (a 40+yr old man), Mark's uncle (a 30+yr old man), and Mark's cousin. All 4 of them had him on the ground and totally beat him up completely and repeatedly. My son came home in tears with a bloody nose and his face/nose was extremely swollen. This all happened in their front/back yard of Marks house.
My son says that Marks uncle was the one who threw the first punch, so he fought back trying to defend himself against a fully grown adult man 20+ years older than him. And once that fight started, Mark and his father and cousin joined in on the fight and just totally beat him up.
I havent taken him to the doctor yet to see if there are any injuries as this happened last night. I am worried his nose my be broken, it was extremely swollen and he says it hurts badly. Is there any way I can take legal action against Mark and his family for this? Or atleast legally force them to pay for any medical bills that may arise because of their assault and injuries caused to my son while on their property? It all happened on Mark's families property, after they agreed to let my son in their house and whatnot. Is it the same as if someone were to get injured in a school, where the school would be liable for the damages?
Any and all responses are appreciated.

