L.A.
There is a wonderful children's book called " Lifetimes". I bet you can check it out, but god to have a copy of it in your child's own collection.
I purchased it and a few other children's books on death, when the mother of one of our daughters preschool classmate was killed in a car accident. Our daughter was 4.
I read it a few days before we told her his mother had died.
Then we wait3ed for her to ask any questions.
Just do not make it a big deal. Children look to how we treat a subject or a situation, to help them know the correct responses.