The investigation agreed that it was virtually impossible for the girls to have got lost and wandered unwittingly from the trail. The investigators also considered it highly unlikely that they had fallen victim to some criminal activity.
A particular part of the trail was identified separately by several investigators as a potential spot where someone
could fall down to one of the tributaries of the Culebra river (the river in which the recovered remains, clothing and backpack were found at various sites). The point where a faller would have landed was independently identified by a local very familiar with the area as the location where the night time pictures were taken.
Someone slipping from the trail at that point would fall up to forty meters and end up in an area surrounded by waterfalls and steep cliffs they wouldn't be able to climb back up from, had they survived the fall to be able to do so. Such a massive fall is apparently also consistent with the state of those of the girls' remains that have been recovered.
The precise details of what happened to Kris and Lisanne will probably never be known, but Kris's parents have expressed their relief at understanding what is likely to have happened to their daughter.
It's incredibly sad to realise that these young women almost certainly died within yards of the trail they disappeared from, and that one or both must have survived for several days before finally passing. It seems there are important lessons to be learned from their deaths.