From Pathfinder Society Scenario #1-03: Escaping the Grave, which isn't enabled.

Collapsing Ceiling (3-4)

HAZARD 3

MECHANICAL TRAP

Stealth +10 (trained)

Description The damaged ceiling is the only thing stopping the centipedes lairing above from falling through.

Disable DC 22 Crafting (trained) to reinforce the ceiling with boards from the broken door.

AC 10; Fort +1, Ref +1

Hardness 5, HP 10 (BT 5); Immunities critical hits, precision

Collapse

Trigger A creature walks into the area beneath the centipede lair.

Effect Hearing potential prey, the centipedes begin scrabbling above, causing the ceiling to collapse and centipedes to rain down, dealing 3d8+4 bludgeoning damage to each creature in the area; each creature in the area must attempt a DC 19 Reflex save.

Critical Success The creature is unaffected.

Success The creature takes half damage.

Failure The creature takes full damage.

Critical Failure The creature takes double damage and is knocked Prone.

Pathfinder Society Scenario #1-03: Escaping the GraveOGL