Gingerbread houses will without warning kill all players inside and teleport thier inventory and backpacks, including all gingerbread loot bags on the ground, out into the ocean to a specific yet differing location. The two reports i found thier items at I28/H28 and D28/E28. Upon return the Gingerbread house is locked with the "despawning" message. I tried to test it for more information and sat inside one for quite a while but it didnt despawn on me, and when i finally left there was no house there at all. I guess for admin these instances do not desapwn as they normally would for a player.
I remember in other such instances there was a feautre, like slowly increasing rads, designed to signal the imminent closure so players can leave. These reportedly had no such warning feature.