Well it was dark. We don’t know the details as far as lighting and such so we don’t know if the SUV driver could have seen them in time.
But the kids doing the pushing should have cleared the road as soon as the headlights of the SUV became visible. It called common sense and self preservation. Many kids today are never taught such a thing.
We can armchair quarterback till the cows come home but it won't change a thing. Who knows; maybe the kids were all talking (bitching) about having to push the car and just got lost in their own heads.
We could ask how someone didn't see them from a distance far enough to avoid hitting them. Didn't any of the kids have white pants, shirts, or shoes on? At this point all we have are questions, 4 dead kids, and 4 grieving families. Tragic.