From Pathfinder Society Scenario #5-16: A Lie Told to Strangers, which isn't enabled.

Crumbling Floor

HAZARD 3

Stealth +10 (trained) to notice the worn flagstones which are crumbling away at the slightest pressure.

Description At a cursory glance the tunnel appears to be little more than a waterlogged chamber.

Disable DC 17 Acrobatics (trained) to safely navigate the wet floor without stepping on any loose masonry or DC 19 Thievery (expert) to cause a controlled collapse without any danger to the PCs.

AC 19; Fort +12, Ref +6

Hardness 10, HP 42 (BT 21); Immunities critical hits, precision

Collapse

Trigger A creature moves into the hazardous area

Effect The flooring crumbles, breaking apart under the creature and sending them into the stagnant water below, dealing 2d12+12 bludgeoning damage (DC 20 basic Reflex save). That creature can use the Grab an Edge reaction to avoid falling.

Pathfinder Society Scenario #5-16: A Lie Told to StrangersOGL