The true meaning of tawakkul is that we do whatever we can, and then leave the rest to Allah. In other words, we put our windows up, take valuable belongings with us, then lock our cars. We then trust that Allah will take care of it for us, and even if something were to happen, we can still find solace in knowing that we did what we could, and that the rest was up to the qadr (decree) of God Almighty.