This effect causes the ceiling to fall when an explosion is detected within the sector. This effect was not used in the game. The intended usage for this effect was probably to seal a window after it has been destroyed by an explosion.

Create the sector with the ceiling which will fall. Place an S[Channel,19] (Speed[0,Speed]) within the sector. The Channel can be used to activate other S[Channel,19] at the same time. It is also logical to place an explosive of some sort in your level.

Notes:

• The message "unlocked" will be displayed when the ceiling begins to drop.
• The game does not check if a shot or object passes through the sector.
• The ceiling will only begin to drop when an explosion occurs somewhere within the sector.
• If any of the sector's walls are using the invisible forcefield effect (i.e. a masked wall with the BIGFORCE (#230) texture), it will be disabled (on both sides of the wall) when an explosion is detected within the sector.