Independent movie where girl finds someone down a well or shaft

[arrowtoes]

I can't remember the name of this movie and so far my google search phrases have been netting me some weird results and nothing accurate. It was a movie I watched several years ago, an independent movie about this young girl who's very isolated and finds this well or some kind of shaft, anyway, and there's someone trapped inside it. But the young girl doesn't tell anyone about it, just keeps coming to visit and talks to them, even brings them food, iirc. Then one day the person inside stops responding and the young girl thinks they must've died. And in the end--spoiler alert necessary?--the young girl throws herself down the well and the movie ends.

Really hoping somebody can help because it is frustrating me how much I can recall and yet all my Google phrasing so far is coming up 100% empty! arrgh