Attempt to get length of upvalue?

Can someone tell me how to fix this script? I keep getting the error:

attempt to get length of upvalue 'TotalSpawns' (a number value)

Code:

local TotalSpawns = 0

for _,v in pairs(script.Parent.Spawns:GetChildren()) do
    if v:IsA("Part") then
        TotalSpawns = TotalSpawns + 1
        print("Total Spawns: "..TotalSpawns)
    end
end


for _,v in pairs(script.Parent.Lava:GetChildren()) do
    v.Touched:connect(function(touch)
        if touch.Parent:FindFirstChild("Humanoid") then
            local ran = math.random(1,#TotalSpawns)
            touch.Parent.HumanoidRootPart.CFrame = script.Parent.Spawns:FindFirstChild("Spawn"..ran).CFrame
        end
    end)
end