My program doesn't have bugs. It just develops random features.
The XFallingVolume sets where you die when you're falling off the edge of the map or building. Now if someone runs off the edge of the building they will fall and then die when they reach the box. (the box will be invisble of course)
This volume actually just damages the player (very heavily), and applies the death messege "Player left a small crater". For game styles such as Onslaught mode, boosting the damage rate in the volume properties will prevent a falling tank from surviving, or taking quite some time to die.
Due to the damaging type of this volume, when the player dies, they usually gib. To kill the player without gibs, see Killing Without Gibbing