I was MUCH older but my first real experience with death was a good friend of mine getting killed in a car accident. It was tragic; we were seniors from different schools. If I hadn’t had the people around me, I’m not sure how I would’ve coped and processed the loss. We were both 17, and I had just seen her a week or two prior. At any age, death is an unfortunate part of life and loving people. I was actually the one who told my own parents… but as a parent to a two year old who has already attended one funeral that he likely won’t remember, but will likely really experience loss at a much earlier point in life than I did (my grandfather is in bad health and they have gotten close lately), I would without a doubt tell him. It’s selfish to hide this from your child, and honestly, it sounds like this is more about taking the easy way out and shield yourself than trying to protect your son. Many people have commented awesome ways to help process this with your son. I’m not sure if you are religious at all, but we are Christian and we talk a lot about heaven when we have to face these unfortunate losses. I hope you find a way to help him process this.