<human>: Can you summarize the given text in a few sentences?

So I'm a senior in high school and at my school we have this thing where all the sports teams travel for a weekend to compete against other schools. It's a big deal for the athletes, especially the seniors because it's the last time they are able to do this. Today was the day where we had a pep-rally to get school spirit up and get the athletes pumped. 

Now recently there has been this 'epidemic' of sorts in my school where like we have at least one person on crutches in every grade. It seems like getting injured iss the new craze. My school isn't that big so the ratio is quite large. One of my friends fractured his ankle and has been using crutches to get around. Because of this I've been teasing him calling him a cripple and whatnot and he's okay with it because he knows I'm just being funny. 

I've sort of adopted this sarcastic mentality to people on crutches and in my last class of the day just before the pep-rally the basketball girl's coach comes in on crutches. Seeing this I blabber out "Oh look, another cripple." I was trying to sound sarcastic and it's supposed to be funny what with the irony of all these people getting injured. But she didn't really laugh and she just sort of gave this sad attempt at a smile. I didn't really think much of it at the time.

Now it's time for the pep-rally and everyone is getting pumped, the girl on crutches is in carried by her teammates in front of the crowd as she is supposed to give a speech (tradition for the captains). She ends up getting really emotional and the coach has to finish for her by saying that she broke her leg at practice and she won't be able to play with her team. This is made even ten times worse because it's her last year and she's a really committed basketball player. 

I'm sitting there feeling like a total retard.
<bot>: A big sports event is about to go down, I sarcastically comment on the captain's injury, turns out she is really emotional about not being able to participate. She prob thinks I'm the biggest asshole.