I was around 9 or 10 and I remember watching this (american) movie around 2005-2006 in color where a girl of short black/maybe dark brown and somewhat goth knew where this underground basement in the middle of perhaps a forest was, so she took her best friend (blonde girly-girl) along with her crush (black somewhat short hair, black clothes) and his best friend (regular guy, no important details on him). I believe the blonde girl and the other guy were a couple, not sure. Anyway, they take things with them such as sleeping bags to sleep in and food, but this short haired girl lies to them saying they are locked in for the sole purpose of wanting to spend time with her crush, but what they don’t know is that she has the key. Things go downhill at some point, her blonde friend becomes ill and vomits in toilet in which later she dies and they find her covered in maggots. Around that same point, they are running out of food. The other guy is somewhere around while the other two are checking out the girl’s dead friend, he opens a can of soda quietly, but the other two hear the sound of it releasing the gas. All of a sudden, I’m not too sure what happens, but the two guys are physically fighting because as stated, they were running out of food so this guy thought his friend wasn’t going to share, meanwhile his best friend was implying he was. The girl’s crush kills his best friend. I’m not sure what happens after, but the girl had climbed the metal chain stairs hanging from the door and shows him the key. Truth is out, the guy becomes furious and violently climbs these chain stairs to the point they break and he falls, a metal tube goes through his stomach and dies. Other things I can’t remember happen, the police eventually arrives one morning, the girl is at her house alone, I believe her parents aren’t home (no idea) and this blond guy is I guess following her around, I really don’t know. I just know he appears at this point, which makes me believe he knows what happened. They’re at this flowing river talking or something. That is all I can recall from the movie.