Should I tell my 93 year old father who is in poor health that his disabled grandson has died in his sleep?

My mom's favorite grandson committed suicide 3 years ago. She was stage 5-6 Alzheimer's at the time. We chose not to tell her.

Thanks for your answer I have thought about it a lot since learning of his death this morning and decided not to tell him. It would only upset him and he would want to know why he wasn't the one taken.

I have a disabled son - he's named after his grandpa. My father adored my son.
I wouldn't - given my own set of dynamics.
If you think your father would be upset by it - and you think you can keep it from him - don't tell him.