Why does my script run when it's only supposed to run when hit by an Explosion?

So when this script runs it's supposed to decrease the value of health then destroy itself only when it's hit by an explosion, but it just does it on it own without being blown up.

local health = script.Parent.Parent.Parent.Health
local debounce = false
local explosion = workspace:FindFirstChild("Explosion")

modelsHit = {}

explosion.Hit:connect(function(part)
if debounce == false then
	debounce = true
end
	part = script.Parent

	if modelsHit[part] then
		return
	end
	
modelsHit[part] = true

	if modelsHit[part] == true then
	health.Value = health.Value - 10
	wait(3)
	debounce = false
	script.Parent:Destroy()
	end
end)