Metal Stairs With Railing Trap
A false floor or trap that will disintegrate when stepped on.
Harvest drops
Iron× 10
Taken apart with a harvesting tool (axe, pickaxe, shovel), before perks and tool bonuses.
When it collapses
Falling, it leaves 
Scrap Metal Pile (60% of the time) where it lands.
Where to find (18 POIs)
Shamway Factory (tier 5), Vanity Tower (tier 5), Diamond's Mens Club (tier 4), Ecotrash Recycling Center (tier 4), HSP Logistics (tier 4), Pineballs Bowling (tier 4), Buy-N-Go Apartments (tier 3), HSP Distribution Center (tier 3), KLZ Radio (tier 3), OK Laundry (tier 3), Ranger Station Golf (tier 3), Regional Paper Company (tier 3), Bombshell News (tier 2), Blue Sky Project (tier 1), Fallen Rock Apartments, Navezgane Public Library, ParKing Garage #1, Rogue Nerds Refuge.
Points of interest built with this block (any of its variants), the highest tiers first, from the game's prefab files.