Quite realistc lasers can be made using a decal as shown here :
http://forum.thegamecreators.com/xt/xt_apollo_pic.php?i=722804
Your entity script can use commands to kill or just reduce health as needed and in such instance no zones are needed.
Not sure that I ever posted a vid of the lasers but they can look good and work very well.
As a decal and not using zones they can can be placed at any tile height so that a player has to jump over them or duck under them as only the actual visible image in a decal provides contact with the player - the invisible parts are ignored by the engine for collision purposes - making them ideal for the need in the light of us not having true particle beams.
"I am and forever will be your friend"