1. Load attached mission (destroyTest.Altis)
2. Take note of your FPS (mine was ~ 51)
3. Press 0-0-1 to level the whole town
4. Wait for the dust to settle
5. Check your FPS now (mine was ~ 23)
6. Press 0-0-2 to flip the player
7. Hold right-mouse button to zoom in and see underground
8. Observe the original houses are underground, presumably causing the FPS loss