Dungeon ni Deai wo Motomeru no wa Machigatteiru Darou ka EP10 (Pass Parade) Procession of Monsters

The party is exploring on the middle floors when another group leads a huge train of monsters to them. They're overwhelmed and caught in a cave-in. Cut off from the upper floors, with limited supplies and little strength left, they are forced to make a desperate attempt to reach the safe zone even deeper in the dungeon.