[Experimental] Projectiles destroy stairs

[Rivet-the-Zombie]

From: http://smf.cataclysmdda.com/index.php?topic=5407.0

as the title states, projectiles that travel over stairs causes the stairs to disappear
not sure if the type of projectile has anything to do with it but I used carbon fiber arrows to shoot a zombie dog in the shelter Im using as a base an now there are no longer stairs to the basement
reloading does not fix the missing stairs

[i2amroy]

Confirmed.

[KA101]

And since stairs aren't player-constructable (especially if this nails upstair-s as well), I'm thinking Blocker. Dammit.