Movie about a GIRL and a BOY who get locked up in lockers for days

[Mike3d]

Hi there I have been looking for the name of this film for so long. I think it's a 90s/2000s film and what I remember is a boy that gets bullied as pushed around until the group of bullies decide to lock him up inside a locker in what I think was an abandoned school. They take him inside a room where I remember there was gray concrete floor and walls. It wasn't a dark room enough sunlight would travel inside the room. The boy I believe relizes There is also a girl locked up in the locker next to him. There were only those two lockers in the room. They are stuck in there for days and they start talking and getting to know each other. The whole movie takes place in that same setting. Well eventually the boy escapes from the locker but is still stuck in the room.  Sure he tries to open the girl's locker but can not open it. Well eventually both start getting in a very unhealthy situation and the boy looks for a water line and gladly he finds one to drink water but couldn't find a way to also feed water to the girl. One day the boy talks to the girl and she doesn't respond. I believe he finally opens the locker or maybe he never even opens her locker but it was too late and she dies. Finally the bullies decide to let him go and he leaves and the movie ends.