pf2e.fyi
From Pathfinder Society Scenario #2-22: Breaking the Storm: Excising Ruination, which isn't enabled.

Collapsing Ramp (7-8)

HAZARD 6
UNCOMMONENVIRONMENTAL
Stealth +15 (expert)
Description Abyssal fire hits the stone beneath the ramp, causing a 15-foot-long section of it to collapse.
Disable DC 28 Crafting (expert) to stabilize the masonry. Each attempt takes 2 actions.
Collapse
Trigger A creature walks onto the collapse site
Effect The triggering creature falls off the Colossus and lands on the ground, taking 40 bludgeoning damage. They can use the Grab an Edge reaction to avoid falling (DC 22 Reflex save).
Pathfinder Society Scenario #2-22: Breaking the Storm: Excising RuinationOGL