"All God's Children"

This is the only film review I've done and might be the only one. But it seems a special case.
"All God's Children" seemed to be a little known film in Australia, I don't know if it received more notice in other countries. It is not overtly Christian or religious, as the title might imply. What happens is this.
The film opens with two boys - one white, one black - stealing a school bus. The the alarm is given, and the audience finds out that it is a type of bus in which the brakes do not work until the engine is warmed up. The boys, not knowing that, are at risk of a serious accident.
The next thing we see is the bus crashing!
After that the action goes into flashback, so that we pick up the plot. It is set against the background of the "bussing" experiment in the U.S. when the government intervened in school enrollments. This was to prevent some schools having only students from middle class or wealthy backgrounds, and others only students from poor backgrounds. The plan was to have a racial and socio-economic mix in each school, and to transport students by bus if necessary to get them to schools outside their area.
In the film, these two boys are staging a protest against it. That is why they stole the bus. The government plan would have the effect of sending them to different schools, and as well as being friends they make an excellent combination on the school football team.
Then the action returns to the present. Police have found the bus crash, with ONE badly burnt body in it. Tests will be needed to learn which of the two it is. The other boy has escaped from the crash, and gone missing. That notches up the tension. The characters in the film, and the audience, are waiting to find out which of the boys has died.
There is quite a lot in the film, revealed through the dialogue. It would get away from the point to go into too much detail about that. As the plot develops, the audience is introduced to both sets of parents, black and white. The dialogue reveals the perspectives of each on the issues of race and education.
At the final moment of the film, we hear that scientific testing has revealed which of the boys was the one found dead in the bus.
The last thing the audience hears is ONE of the mothers crying heartbrokenly, having learned that she has lost her child.
But the audience never finds out which of them it is. And that is the point that we are confronted with.
Does it make it any better, which one of them it is? Isn't is just as bad, either way?
I can't remember the names of any cast members except ( I think) Richard Widmark. The film was made back in the 1970s. It seemed to receive little acclaim, but I thought it made an excellent point. We are ALL God's children. Race does not change our value. Neither, it could be added does gender. But that would be another story.