*There appear to be trails in both directions. Time spent searching might indicate which is the fresher, but that would also be time spent losing more ground, so they decide to at least check to the left for a bit. After continuing for a while, they find a hole where part of the floor has crumbled away, but it is filled up with rubble, though it might be possible for someone to squeeze through and down if they were very small or extraordinarily flexible. If they walk around that, eventually there is a point in the hallway where a lot of rubble fills up much of the passage, but it does look like they might be able to squeeze over and through the rubble and continue straight ahead if they worked at moving it or if any of them was skilled at squeezing through tight spots (Escape Artist check). It looks like if even one person could get through, it should be easy to clear a wider path from both sides at once.*