how do i make my spreading fire kill players?

i got this script. its a fire and when it touches a part the part burns too. so it spreads, sometime the burning parts explode. but the burning parts deal no damage. any ideas:

function OnTouched(hit)
    if hit == nil then
        return
    end
    if hit.Parent == nil then
        return
    end
    if hit.Anchored == true and hit.Locked == true then
        return end
    if hit.Name == script.Parent.Name then 
        return end

    if hit.Name == "Engine" then 
        return end  

    hit.Anchored = false
    hit.Name = script.Parent.Name
    hit.Color = Color3.new()

    fire = Instance.new("Fire")
    fire.Parent = hit
    fire.Heat = 0
    fire.Size = 30

    sound1 = Instance.new("Sound")
    sound1.Parent = hit
    sound1.SoundId = "http://www.roblox.com/asset/?id=31760113"
    sound1.Looped = true
    sound1:Play()


    wait(math.random(5,10))
    script:clone().Parent = hit

    wait(math.random(5,10))

    hit:BreakJoints()

    hit.Color = Color3.new("")

    wait(math.random(5,10))

    e = Instance.new("Explosion")
    e.Parent = game.Workspace
    e.Position = hit.Position

    sound2 = Instance.new("Sound")
    sound2.Parent = hit
    sound2.SoundId = "http://www.roblox.com/asset/?id=16976189"
    sound2.Pitch = 0.75
    sound2:Play()

    hit.Velocity = Vector3.new(0, 100, 0)

    hit.Size = hit.Size/Vector3.new(2,2,2)

    wait(math.random(5,10))

    hit:remove()

    sound1:Stop()

end

script.Parent.Touched:connect(OnTouched)