Ponyboy is the least hurt of the three after the incident with the abandoned church catching on fire. Ponyboy doesn’t go back into the church like Dallas and Johnny, and that means he doesn’t suffer the same level of damage as they do. Dally and Johnny are injured by falling timber, and they receive numerous burns all over their bodies.
Ponyboy is only in the hospital for a little while before he is released. He is driven there by Jerry, the school teacher, and his brothers Sodapop and Darry visit him. Soda and Darry are family, and that means they are legally allowed to visit Ponyboy in the hospital. While they are there, reporters and police officers swarm them and ask them a ton of questions.
After the police and reporters leave, Ponyboy wants to visit Dallas and Johnny, but they are not allowed to because they aren’t family:
The nurses wouldn't tell us anything about Johnny and Dally, so Darry got hold of the doctor. The doctor told us that he would talk only to the family, but Darry finally got it through the guy's head that we were about as much family as Dally and Johnny had. (chapter 7)
They are given some information, and eventually, Pony is permitted to see Johnny, who ultimately dies of his injuries. The irony of the entire situation is that Johnny’s mother comes to see him, but he refuses to see her; despite her being a legal family member, he doesn’t consider her family as he thinks of the gang.