How do you get the key from an inserted value in a a table?

So I'm trying to tween a model so it builds bricks from a point. However, the result I get is this.

Any help? Here is the script:

ts = game:GetService('TweenService')
CFrames = {}
BricksBuilt = 0

wait(1)

for i,v in next, workspace.ItemQ:GetChildren() do
	table.insert(CFrames, v.CFrame)
	v.CFrame = workspace.QPos.CFrame
end

BuildBrick = function(child)
	local info = TweenInfo.new(
		1,
		Enum.EasingStyle.Quint,
		Enum.EasingDirection.Out,
		0,
		false,
		0
	)	
	local goals = {
		CFrame = CFrames[BricksBuilt]
	}	
	local tween = ts:Create(child,info,goals)
	tween:Play()
	BricksBuilt = BricksBuilt + 1
end

for i,v in next, workspace.ItemQ:GetChildren() do
	spawn(function() BuildBrick(v) end)
	wait(0.01)
end