Children 3 years and under don't generally understand death. If your child hasn't asked about suicide or had personal experience with it, Westers says there's no need to bring up the topic at this age. If you need to communicate that a close family member or friend has died by suicide, it's best to keep it short and simple.
"Discuss the death in the same terms you would discuss death by any physical illness," Westers says. "For example, say 'I have some sad news to share with you. Grandpa died, which means his body stopped working and can't be fixed, so we won't be able to see him again.' In the unlikely event that a child this age asks what suicide is, try to stick to explaining the concept of death first."