The ruins are starting to flood. Where can I go?

Once Belial has killed the worm, you need to get out of there quickly before
you drown.  And there's only place you can go.

Turn to the south from the worm's location, and then take the first
passageway to the west.

You'll see a floating pallet there.

Climb on it.

Then wait until it takes you up to another level of the ruins.

You'll find something else to float on, on that level.

There's a door at the edge of a pit.

Push the door into the pit and wait until it floats up to you.