Where Susan, Carter and Scoggs have just witnessed the death of Janice in the elevator shaft, they get resuced by Preacher. Preacher uses sheets tied together and you can clearly see the sheets being dragged back up, through the watertight door and the door slamming.

A few scenes later when Scoggs and Carter go back into the water, you see the elevator shaft and the remains of the sheets tied together caught in the water tight door and hanging down the shaft and into the water.