Help Bones get medical treatment

Today my grandchildren's 5 year old Chi-wienie got out of their yard and was hit by a car. Hit n run.  My daughter and husband cannot afford the unexpected vet bills.  At this point his injuries are both hind legs broken, dislocated hip and rectal prolapse. They have to do more xrays to check his other organs.  They were already given an estimate of almost $900. This is my grandchildren's first dog. He is family and has a brother waiting at home for him.. They are trying to do everything possible to save him.  Any help would be greatly appreciated.