Doors and elevators in the map editor are walls that can basicly move.They can move when a player pushes a switch or enter a region which open the door automaticly.They can come in different shapes and sizes.They also can come with different speed.Sometimes,if a door or elevator is fast enough,if you get in a certain body position,it can kill you.For example.A pretty fast elevator is going up.You decide to lie down.Your body can get smashed that way bacuase your body is going down when the elevator is going up.The unequal force forces you in the elevator which destroyes your body.If you are standing up and the elevator is going up fast,it can happen.It is also possible it can shoot you into the air from all the pent up speed.