Walls and other objects that are very difficult to destroy it on the editor are easily destroy on Internet. I even try to protect them with:

{_x EnableSimulation False; _x AllowDamage False;} ForEach (NearestObjects [Centre,["Static"],300]);

But walls and other objects are destroyed by a non recognized source. I guess the destruction can be due to defected bullets or due to rag doll collisions. I manage to see how a dead AI corpse hit a group of boxes and boxes were destroyed by the collision.