It was movie about a train that hit the a school bus full of kids and how the town had to keep going. I don't remember if all kids where killed, and I think it was a true story. Don't remember much more, just that there was a song and it was like when they were in church singing you could hear the next train.
I know this isn't much help but maybe someone remebers it.

Not sure, but maybe PopStar | Cloris Leachman | Long Journey Back, Movie Trailer (http://www.popstar.com/Cloris_Leachman/Videos/Movie/Long_Journey_Back/). If not, when approximately was it made?

I looked into Long Journey back and it only talks about one girl, ths was a whole town learning to deal with it. I remember every time the town heard the whistle it was devastating.
It had to be in the late 80's or 90's. I want to say the song was day by day, for some reason that is sticking to my head.

The Sweet Hereafter (1997) (http://www.imdb.com/title/tt0120255/)?

I've seen The Sweet Hereafter (1997)? And that's not the one.
I do have a questions about POPSTAR- long journey back.. Does anyone know if you can purchase that movie? I have looked everywhere. There is one on Amazon that they want 54 bucks for it.

Thanks for helping.