Не могу понять, почему removeChild выдаёт эту ошибку

Код AS3:
var bullet_mc:Bullet;
var debries:Array = new Array();
var debrieNum:uint = 0;
var speed:uint = 10;
var debriesTimer:Timer = new Timer(60);
stage.addEventListener(MouseEvent.MOUSE_DOWN, debriesOn)
function debriesOn(e:Event):void
{
debriesTimer.addEventListener(TimerEvent.TIMER, trailFunc);
debriesTimer.start();
stage.addEventListener(MouseEvent.MOUSE_UP, debriesOff);
}
function debriesClear():void
{
for(var i:int=debries.length - 1; i>=0 ; i--)
{
trace(debries[i]);
removeChild(debries[i]);
debries.splice(0,1);
debriesTimer.stop();
debriesTimer.removeEventListener(TimerEvent.TIMER, trailFunc);
}
}
function debriesOff(e:Event):void
{
debriesClear();
}
function trailFunc(e:Event):void
{
bullet_mc = new Bullet();
addChild(bullet_mc);
bullet_mc.name = "debrie" + debrieNum;
if(debrieNum <= 25)
{
bullet_mc.x = mouseX + Math.random()*(10 + debrieNum);
bullet_mc.y = mouseY + Math.random()*(10 + debrieNum);
}
else
{
bullet_mc.x = mouseX + Math.random()*10;
bullet_mc.y = mouseY + Math.random()*10;
}
debrieNum ++;
debries.push(bullet_mc);
//trace(trailNum);
//debriesClear();
}
Упс...извиняюсь,в названии не тот код ошибки указал! Ошибка № 2025 - The supplied DisplayObject must be a child of the caller.
at flash.display:

isplayObjectContainer/removeChild()