Board Thread:General Discussion/@comment-15494492-20160423211921

So as we all know, there were six other humans that came through the Underground before Frisk. All of them must have come into contact with Toriel, since the Ruins lead into the rest of the Underground. This is of course further supported by the symbolic tree outside her home and her monologue preceding her encounter.

That being said, why did Toriel never destroy the exist to the Ruins before Frisk fell down? One would think that after one, two, three, and so on cases of humans falling down(assumedly children) that Toriel would figure out that this was her only option, since all six of the previous cases resulted in their deaths. What made Frisk so special(other than the obvious resemblance to Chara)? 