How to write a sentence that is suitable for friends to express "Grandpa passed away"?

1, Grandpa's sudden death brought us all an unspeakable heartache.

2. Because no one thought before, how could grandpa, who has been so healthy and has almost no cold, suddenly leave?

If we can do it all over again, we will spend more time with you and talk to you, so that Grandpa will no longer feel lonely.

If we can do it all over again, we won't always make grandpa angry and make you laugh, but it's too late!

Dear friends and relatives, my grandfather died on a certain day of a certain year due to medical treatment!