Randomly selecting blocks in an array?

I have 30 anchored blocks. This script is intended to randomly select one block, and make it fall. It doesn't work though, and I can't figure out why.

Side note: I did assign CFrame positions to them all, I excluded them from the code below though because it's not relevant to the issue

    Tiles = Instance.new("Model")
    Tiles.Parent = game.Workspace
    Tiles.Name = "Tiles"
    Tiles.Archivable = true
    brickArray = {}

for i=1,30, 1 do
Brick = Instance.new("Part")
    Brick.Name = "Brick" .. i
    table.insert(brickArray, Brick.Name)
    Brick.Parent = game.workspace.Tiles
    Brick.Anchored = true
    Brick.Size = Brick.Size + Vector3.new(20,0,22)
    Brick.BrickColor = BrickColor.Random()
    Brick.Locked = false
end

while length >= 1 do
    i = math.ceil(math.random(1,length))
    print(i)
    v = brickArray[i]
    print(v)
        if v ~= nil then
        brickArray[i].Anchored = false
        game:GetService("Debris"):AddItem(v,"3")
    end
    wait(.2)
end