You know, my engineer's heart was crying in pain during those air vent escapes, because those things aren't neither made to allow for a human to pass through them, nor to resist the weight of a person (much less 7 at the same time). Though, I usually handwave these things in favor of the narrative, I was going to ask
@TheWindel say that the vent collapsed because it became too much of a cheap trick, good thing it already did without need of interference to preserve the drama.
To say the truth, I think that Saya was being idotic to not put a hell of a lot of trap on the most obvious escape route.