It's implied another human came down before you and was murdered because of the training dummy's stuffing being torn out and falling on the ground and the spikes being covered in blood.
They're also in complete disarray. The water is dirty and filled with algae, the walls are cracked and covered in vines, and that's not even mentioning that the monster candy room is completely inaccessible because the wall has caved in.
Tear Jerker: Aliza's whole situation is this. She was bullied into going down into the mountain and thrust into a world where literally everything wants to kill her. Her self-loathing when Toriel leaves is downright heartbreaking.