Looking at your album that is working as intended. If you have a base mesh , in this instance your wall, that is setup with your FBX chunks and you destroy the wall while the game is running the simulation will revert back when you stop the game.
The simulation may be slightly different every time and not result in the objects always being in the same place.
If you need a setup like that it may be better solution to import several chunks as static meshes and set them to a collision type of Physics Actor. You can place them in your scene in the position you want them to be and when a player or other object collides with them they will move. This is similar to the white physics cubes in the first person template.